boolean android.app.Activity.isFinishing()函数使用

最新推荐文章于 2022-09-25 20:32:04 发布
转载 最新推荐文章于 2022-09-25 20:32:04 发布 · 1.2k 阅读 · 0

本文探讨了Android开发中Activity在finish状态下的常见问题，包括如何避免在Activity已finish时仍接收广播导致的bug，以及如何处理finish状态下发送消息引发的问题。

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这个函数注释：

Check to see whether this activity is in the process of finishing, either because you called finish on it or someone else has requested that it finished. This is often used in onPause to determine whether the activity is simply pausing or completely finishing.

Returns:
If the activity is finishing, returns true; else returns false.
See Also:
finish
判断this Activity是否finish，自己调用或者某种因素请求finish，经常用在onPause函数里面


这次项目中，遇到这个问题，一个activity在finish时候，还有收到广播，结果导致bug

在广播接收器中先判断一下比较保险。或者在onDestroy里面注销广播

private BroadcastReceiver mIntentReceiver = new BroadcastReceiver()
    {
        @Override
        public void onReceive(Context context, Intent intent)
        {
            Log.d(TAG, intent.toString());    
            final String action = intent.getAction();
            
            if(isFinishing())
            {

                  。。。。。。。              

                return;

            }

}


还有遇到一个问题，在activity  finish时候，这时候handler.sendMessage，这时候也会导致bug

这时候最好在finish函数里面removeAllCallbackAndMessage(this)

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AndroidManifest.xml：<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.diaryapp"> <uses-feature android:name="android.hardware.camera" android:required="false" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.CAMERA" /> <application android:allowBackup="true" android:hardwareAccelerated="true" android:largeHeap="true" android:requestLegacyExternalStorage="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/Theme.HelloWorld"> <activity android:name=".MainActivity" android:label="@string/title_activity_main" android:exported="false" /> <activity android:name=".DiaryActivity" android:label="@string/title_activity_diary" android:exported="false" /> <activity android:name=".RegisterActivity" android:label="@string/title_activity_register" android:exported="false" /> <activity android:name=".LoginActivity" android:label="@string/title_activity_login" android:exported="true"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest> DiaryAdapter： package com.example.diaryapp.adapters; import android.annotation.SuppressLint; import android.content.Context; import android.content.Intent; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.TextView; import androidx.annotation.NonNull; import androidx.recyclerview.widget.RecyclerView; import com.example.diaryapp.utils.GlideEngine; import com.example.diaryapp.DiaryActivity; import com.example.diaryapp.R; import com.example.diaryapp.models.Diary; import java.util.List; public class DiaryAdapter extends RecyclerView.Adapter<DiaryAdapter.DiaryViewHolder> { private Context context; private List<Diary> diaryList; private int userId; public DiaryAdapter(Context context,List<Diary> diaryList,int userId){ this.context=context; this.diaryList=diaryList; this.userId=userId; // 通过构造函数传递 userId } // 当数据更新时调用此方法 @SuppressLint("NotifyDataSetChanged") public void updateDiaries(List<Diary> newDiaries){ this.diaryList.clear(); this.diaryList.addAll(newDiaries); notifyDataSetChanged(); } @NonNull @Override public DiaryAdapter.DiaryViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { View view= LayoutInflater.from(context).inflate(R.layout.item_diary,parent,false); return new DiaryViewHolder(view); } // 绑定视图持有者方法 @Override public void onBindViewHolder(@NonNull DiaryAdapter.DiaryViewHolder holder, int position) { Diary diary=diaryList.get(position); holder.tvTitle.setText(diary.getTitle()); holder.tvDate.setText(diary.getDate()); holder.tvContent.setText(diary.getContent()); holder.tvWordCount.setText("字数：" + diary.getContent().length()); if (diary.getImagePath() != null && !diary.getImagePath().isEmpty()) { GlideEngine engine = GlideEngine.createGlideEngine(); engine.loadImage(context,diary.getImagePath(),holder.ivImage); } else { holder.ivImage.setBackgroundColor(context.getResources().getColor(android.R.color.darker_gray)); } holder.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent=new Intent(context, DiaryActivity.class); intent.putExtra("diaryId",diary.getId()); intent.putExtra("userId",userId); // 确保传递正确的 userId context.startActivities(new Intent[]{intent}); } }); } @Override public int getItemCount() { return diaryList.size(); } public static class DiaryViewHolder extends RecyclerView.ViewHolder { private TextView tvTitle,tvDate,tvContent,tvWordCount; private ImageView ivImage; public DiaryViewHolder(@NonNull View itemView) { super(itemView); tvTitle=itemView.findViewById(R.id.tvTitle); tvDate=itemView.findViewById(R.id.tvDate); tvContent=itemView.findViewById(R.id.tvContent); ivImage=itemView.findViewById(R.id.ivImage); tvWordCount=itemView.findViewById(R.id.tvWordCount); } } } Diary：package com.example.diaryapp.models; public class Diary { private int id; private String title; private String content; private String date; private String imagePath; public Diary(){} public int getId() { return id; } public void setId(int id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getContent() { return content; } public void setContent(String content) { this.content = content; } public String getDate() { return date; } public void setDate(String date) { this.date = date; } public String getImagePath() { return imagePath; } public void setImagePath(String imagePath) { this.imagePath = imagePath; } } DatabaseHelper：package com.example.diaryapp.utils; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; import com.example.diaryapp.models.Diary; import java.util.ArrayList; import java.util.List; public class DatabaseHelper extends SQLiteOpenHelper { //数据库信息 private static final String DATABASE_NAME = "DiaryApp.db"; private static final int DATABASE_VERSION = 1; //用户表信息 private static final String TABLE_USER = "user"; private static final String COLUMN_USER_ID = "id"; private static final String COLUMN_USER_USERNAME = "username"; private static final String COLUMN_USER_PASSWORD = "password"; //日记表信息 private static final String TABLE_DIARY = "diary"; private static final String COLUMN_DIARY_ID = "id"; private static final String COLUMN_DIARY_USER_ID = "user_id"; private static final String COLUMN_DIARY_TITLE = "title"; private static final String COLUMN_DIARY_CONTENT = "content"; private static final String COLUMN_DIARY_DATE = "date"; private static final String COLUMN_DIARY_IMAGE_PATH = "image_path"; public DatabaseHelper(Context context) { super(context, DATABASE_NAME,null,DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { //创建用户表 String createUserTable = "CREATE TABLE " + TABLE_USER + " (" + COLUMN_USER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_USER_USERNAME + " TEXT UNIQUE, " + COLUMN_USER_PASSWORD + " TEXT)"; db.execSQL(createUserTable); //创建日记表 String createDiaryTable = "CREATE TABLE " + TABLE_DIARY + " (" + COLUMN_DIARY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_DIARY_USER_ID + " INTEGER, " + COLUMN_DIARY_TITLE + " TEXT, " + COLUMN_DIARY_CONTENT + " TEXT, " + COLUMN_DIARY_DATE + " TEXT, " + COLUMN_DIARY_IMAGE_PATH + " TEXT)"; db.execSQL(createDiaryTable); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { //升级数据库时的操作 db.execSQL("DROP TABLE IF EXISTS " + TABLE_USER); db.execSQL("DROP TABLE IF EXISTS " + TABLE_DIARY); onCreate(db); } //用户相关操作 public long addUser(String username,String password){ SQLiteDatabase db = null; try { db=this.getWritableDatabase(); ContentValues values = new ContentValues(); values.put(COLUMN_USER_USERNAME, username); values.put(COLUMN_USER_PASSWORD,password); return db.insert(TABLE_USER,null,values); }catch (Exception e){ e.printStackTrace(); return -1; }finally { if (db!=null){ db.close(); } } } public boolean checkUser(String username, String password){ SQLiteDatabase db = null; Cursor cursor = null; boolean exists = false; try { db=this.getReadableDatabase(); cursor = db.rawQuery( "SELECT * FROM " + TABLE_USER + " WHERE " + COLUMN_USER_USERNAME + "=? AND " + COLUMN_USER_PASSWORD + "=?", new String[]{username,password} ); exists = cursor.getCount() > 0; }catch (Exception e){ e.printStackTrace(); }finally { if (cursor != null){ cursor.close(); } if (db!=null){ db.close(); } } return exists; // Cursor cursor = db.rawQuery( // "SELECT * FROM " + TABLE_USER + " WHERE " + // COLUMN_USER_USERNAME + "=? AND " + COLUMN_USER_PASSWORD + "=?", // new String[]{username,password} // ); // boolean exists = cursor.getCount() > 0; // Log.d("DatabaseHelper","checkUser: username=" + username + ", exists=" + exists); // cursor.close(); // return exists; } public int getUserId(String username){ SQLiteDatabase db = null; Cursor cursor=null; int userId=-1; try { db = this.getReadableDatabase(); cursor = db.rawQuery( "SELECT " + COLUMN_USER_ID + " FROM " + TABLE_USER + " WHERE " + COLUMN_USER_USERNAME + "=?", new String[]{username} ); if (cursor.moveToFirst()) { // 如果cursor不为空且移动到第一条记录，获取用户ID userId = cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_USER_ID)); } }catch (Exception e){ e.printStackTrace(); }finally { if (cursor!=null){ cursor.close(); } if (db!=null){ db.close(); } } return userId; } //日记相关操作 public long addDiary(int userId, Diary diary){ SQLiteDatabase db = getWritableDatabase(); try { db.beginTransaction(); ContentValues values = new ContentValues(); values.put(COLUMN_DIARY_USER_ID, userId); values.put(COLUMN_DIARY_TITLE,diary.getTitle()); values.put(COLUMN_DIARY_CONTENT,diary.getContent()); values.put(COLUMN_DIARY_DATE,diary.getDate()); values.put(COLUMN_DIARY_IMAGE_PATH,diary.getImagePath()); long result = db.insert(TABLE_DIARY,null,values); db.setTransactionSuccessful(); return result; }catch (Exception e){ e.printStackTrace(); return -1; }finally { db.endTransaction(); // if (db != null){ // db.endTransaction(); // db.close(); // } } } public List<Diary> getDiariesByUserId(int userId){ List<Diary> diaries = new ArrayList<>(); SQLiteDatabase db = getReadableDatabase(); Cursor cursor = null; try { db = this.getReadableDatabase(); cursor = db.rawQuery( "SELECT * FROM " + TABLE_DIARY + " WHERE " + COLUMN_DIARY_USER_ID + "=? ORDER BY " + COLUMN_DIARY_DATE + " DESC", new String[]{String.valueOf(userId)} ); while (cursor.moveToNext()) { Diary diary = new Diary(); diary.setId(cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_DIARY_ID))); diary.setTitle(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_TITLE))); diary.setContent(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_CONTENT))); diary.setDate(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_DATE))); diary.setImagePath(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_IMAGE_PATH))); diaries.add(diary); } }catch (Exception e){ e.printStackTrace(); }finally { if (cursor != null){ cursor.close(); } // if (db != null){ // db.close(); // } } return diaries; } public Diary getDiaryById(int diaryId){ SQLiteDatabase db = getReadableDatabase(); Cursor cursor = null; try { db = this.getReadableDatabase(); cursor = db.rawQuery( "SELECT * FROM " + TABLE_DIARY + " WHERE " + COLUMN_DIARY_ID + "=?", new String[]{String.valueOf(diaryId)} ); if (cursor.moveToFirst()) { Diary diary = new Diary(); diary.setId(cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_DIARY_ID))); diary.setTitle(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_TITLE))); diary.setContent(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_CONTENT))); diary.setDate(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_DATE))); diary.setImagePath(cursor.getString(cursor.getColumnIndexOrThrow(COLUMN_DIARY_IMAGE_PATH))); return diary; } }catch (Exception e){ e.printStackTrace(); }finally { if (cursor != null){ cursor.close(); } // if (db != null){ //// db.close(); // 确保关闭数据库连接 // } } // cursor.close(); return null; } public long updateDiary(Diary diary){ SQLiteDatabase db = getWritableDatabase(); try { ContentValues values = new ContentValues(); values.put(COLUMN_DIARY_TITLE,diary.getTitle()); values.put(COLUMN_DIARY_CONTENT,diary.getContent()); values.put(COLUMN_DIARY_DATE,diary.getDate()); values.put(COLUMN_DIARY_IMAGE_PATH,diary.getImagePath()); return db.update(TABLE_DIARY, values, COLUMN_DIARY_ID + "=?", new String[]{String.valueOf(diary.getId())}); // db.close(); // 确保关闭数据库连接 // Log.d("DatabaseHelper","updateDiary: result=" + result); //调试日志 // return result; }catch (Exception e){ e.printStackTrace(); return -1; }finally { // if (db != null){ // db.close(); // } } } public void deleteDiary(int diaryId) { SQLiteDatabase db = getWritableDatabase(); try { db.beginTransaction(); db.delete(TABLE_DIARY, COLUMN_DIARY_ID + "=?", new String[]{ String.valueOf(diaryId) }); db.setTransactionSuccessful(); }catch (Exception e){ e.printStackTrace(); }finally { db.endTransaction(); } // finally { // if (db != null){ // db.close(); // } } // int result=db.delete(TABLE_DIARY, // COLUMN_DIARY_ID + "=?", // new String[]{String.valueOf(diaryId)}); // db.close(); // 确保关闭数据库连接 // Log.d("DatabaseHelper","deleteDiary: result=" + result);//调试日志 // } } GlideEngine：package com.example.diaryapp.utils; import android.content.Context; import android.widget.ImageView; import com.bumptech.glide.Glide; import com.bumptech.glide.load.resource.bitmap.CenterCrop; import com.bumptech.glide.load.resource.bitmap.RoundedCorners; import com.example.diaryapp.R; import com.luck.picture.lib.engine.ImageEngine; import com.luck.picture.lib.utils.ActivityCompatHelper; public class GlideEngine implements ImageEngine { @Override public void loadImage(Context context, String url, ImageView imageView) { if (!ActivityCompatHelper.assertValidRequest(context)) { return; } try { Glide.with(context) .load(url) .into(imageView); } catch (Exception e) { e.printStackTrace(); imageView.setBackgroundColor(context.getResources().getColor(android.R.color.darker_gray)); } } @Override public void loadImage(Context context, ImageView imageView, String url, int maxWidth, int maxHeight) { if (!ActivityCompatHelper.assertValidRequest(context)) { return; } Glide.with(context) .load(url) .override(maxWidth, maxHeight) .into(imageView); } @Override public void loadAlbumCover(Context context, String url, ImageView imageView) { if (!ActivityCompatHelper.assertValidRequest(context)) { return; } Glide.with(context) .asBitmap() .load(url) .override(180, 180) .sizeMultiplier(0.5f) .transform(new CenterCrop(), new RoundedCorners(8)) .placeholder(R.drawable.ic_launcher_background) .into(imageView); } @Override public void loadGridImage(Context context, String url, ImageView imageView) { if (!ActivityCompatHelper.assertValidRequest(context)) { return; } Glide.with(context) .load(url) .override(200, 200) .centerCrop() .placeholder(R.drawable.ic_launcher_background) .into(imageView); } @Override public void pauseRequests(Context context) { Glide.with(context).pauseRequests(); } @Override public void resumeRequests(Context context) { Glide.with(context).resumeRequests(); } private GlideEngine() { } private static final class InstanceHolder { static final GlideEngine instance = new GlideEngine(); } public static GlideEngine createGlideEngine() { return InstanceHolder.instance; } }DiaryActivity：package com.example.diaryapp; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.graphics.Bitmap; import android.net.Uri; import android.os.Bundle; import android.provider.MediaStore; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; import androidx.activity.EdgeToEdge; import androidx.appcompat.app.AppCompatActivity; import com.example.diaryapp.models.Diary; import com.example.diaryapp.utils.DatabaseHelper; import com.example.diaryapp.utils.GlideEngine; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.Date; public class DiaryActivity extends AppCompatActivity { // 声明界面组件和相关变量 private EditText etTitle,etContent; private TextView tvDate; private ImageView ivImage; private Button btnSave,btnDelete,btnAddImage; private DatabaseHelper dbHelper; private int userId; private int diaryId = -1; private String imagePath; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); EdgeToEdge.enable(this); setContentView(R.layout.activity_diary);// 设置布局文件 // 获取传递过来的用户ID和日记ID userId = getIntent().getIntExtra("userId",-1); diaryId = getIntent().getIntExtra("diaryId",-1); if (userId == -1){ // 检查用户ID是否有效 // 用户ID无效，可能是登录流程的问题 Toast.makeText(this, "用户ID无效", Toast.LENGTH_SHORT).show(); finish(); return; } // 初始化界面组件 initView(); // 如果是编辑日记，加载日记内容 if (diaryId != -1){ Diary diary=dbHelper.getDiaryById(diaryId); if (diary != null){ etTitle.setText(diary.getTitle()); // 设置日记标题 etContent.setText(diary.getContent()); // 设置日记内容 tvDate.setText(diary.getDate()); // 设置日记日期 imagePath=diary.getImagePath(); // 获取图片路径 if (imagePath != null && !imagePath.isEmpty()) { try { // 使用Glide加载图片 GlideEngine engine = GlideEngine.createGlideEngine(); engine.loadImage(this, imagePath, ivImage); } catch (Exception e) { e.printStackTrace(); ivImage.setBackgroundColor(getResources().getColor(android.R.color.darker_gray)); // 设置默认背景 } } // 显示删除按钮 btnDelete.setVisibility(View.VISIBLE); }else { // 日记ID无效，可能是数据库查询的问题 Toast.makeText(this, "日记ID无效", Toast.LENGTH_SHORT).show(); finish(); } }else { // 设置当前日期 tvDate.setText(getCurrentDate()); } // 添加图片按钮监听 btnAddImage.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { //selectImage(); // 改：if (!view.isEnabled() || !view.isClickable()){ // return; // } showImageOptions(); // 显示添加图片选项 } }); // 保存按钮监听 btnSave.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { // 改：if (!view.isEnabled() || !view.isClickable()){ // return; // } saveDiary(); // 保存日记 } }); // 删除按钮监听 btnDelete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { // 改：if (!view.isEnabled() || !view.isClickable()){ // return; // } deleteDiary(); // 删除日记 } }); } // private void selectImage() { // // 创建选择图片的Intent // Intent pickIntent=new Intent(Intent.ACTION_GET_CONTENT); // pickIntent.setType("image/*"); // // // 创建拍照的Intent // Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); // if (captureIntent.resolveActivity(getPackageManager()) != null) { // startActivityForResult(captureIntent,2); // } // //intent.setAction(Intent.ACTION_GET_CONTENT); // startActivityForResult(pickIntent,1); // } private void showImageOptions() { // 创建弹出菜单，提供两个选项：从图库选择和拍照 String[] options = {"从图库选择","拍照"}; new AlertDialog.Builder(this) .setTitle("添加图片") .setItems(options,(dialog,which) -> { if (which == 0){ //从图库选择 Intent pickIntent = new Intent(Intent.ACTION_GET_CONTENT); pickIntent.setType("image/*"); startActivityForResult(pickIntent,1); }else if (which == 1){ //拍照 Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); if (captureIntent.resolveActivity(getPackageManager()) != null){ startActivityForResult(captureIntent,2); }else { Toast.makeText(DiaryActivity.this, "无法调用摄像头", Toast.LENGTH_SHORT).show(); } } }) .show(); } private void saveDiary() { String title=etTitle.getText().toString().trim(); String content=etContent.getText().toString().trim(); String date=tvDate.getText().toString(); if (title.isEmpty() || content.isEmpty()){ // 检查输入是否为空 return; } Diary diary=new Diary(); diary.setTitle(title); diary.setContent(content); diary.setDate(date); diary.setImagePath(imagePath); // 确保图片路径不为空 if (diaryId != -1){ diary.setId(diaryId); dbHelper.updateDiary(diary); // 更新日记 }else { dbHelper.addDiary(userId,diary); // 添加新日记 } //返回主界面 Intent resultIntent = new Intent(); setResult(RESULT_OK,resultIntent); finish(); } private void deleteDiary() { // //删除日记 // dbHelper.deleteDiary(diaryId); new AlertDialog.Builder(this) .setTitle("确认删除") .setMessage("确定要删除这篇日记吗？") .setPositiveButton("删除", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // 使用独立的 DatabaseHelper 实例执行删除操作 DatabaseHelper helper=new DatabaseHelper(DiaryActivity.this); helper.deleteDiary(diaryId); // dbHelper.deleteDiary(diaryId); // 删除日记 // 设置结果码为RESULT_OK，表示操作成功,返回主界面MainActivity Intent resultIntent = new Intent(); setResult(RESULT_OK,resultIntent); finish(); } }) .setNegativeButton("取消",null) .show(); } @Override protected void onDestroy() { super.onDestroy(); // 释放可能持有的资源 if (btnSave!=null){ btnSave.setOnClickListener(null); } if (btnDelete!=null){ btnDelete.setOnClickListener(null); } if (btnAddImage!=null){ btnAddImage.setOnClickListener(null); } } @Override protected void onPause() { super.onPause(); // 暂停时释放资源 if (isFinishing()) { // 清理可能的临时资源 } } @Override protected void onResume() { super.onResume(); // 恢复时重新初始化资源 } private String getCurrentDate(){ // 返回当前日期的字符串表示 return new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()); } protected void onActivityResult(int requestCode,int resultCode,Intent data){ super.onActivityResult(requestCode,resultCode,data); if (isFinishing() || isDestroyed()){ return; } // 确保调用super.onActivityResult if (requestCode == 1 && resultCode == RESULT_OK && data != null){ // 处理从图库选择的图片 Uri selectedImage = data.getData(); if (selectedImage != null) { // 检查selectedImage是否为null try { // 将图片保存到应用私有目录 Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), selectedImage); String filename = "diary_image_" + System.currentTimeMillis() + ".jpg"; File file = new File(getExternalFilesDir(null), filename); // File fileDir = getExternalFilesDir(null); // if (fileDir != null && !fileDir.exists()){ // fileDir.mkdir(); // } // File file = new File(fileDir,filename); FileOutputStream fos = new FileOutputStream(file); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos); fos.flush(); fos.close(); imagePath = file.getAbsolutePath(); // 改：ivImage.setImageBitmap(bitmap); // 显示图片 // 使用Glide加载图片 GlideEngine engine = GlideEngine.createGlideEngine(); engine.loadImage(this, imagePath, ivImage); } catch (IOException e) { e.printStackTrace(); //改： ivImage.setBackgroundColor(getResources().getColor(android.R.color.darker_gray)); } } // Glide.with(this).load(imagePath).into(ivImage); // }catch (IOException e){ // e.printStackTrace(); // } }else if (requestCode == 2 && resultCode == RESULT_OK && data != null){ //处理拍照结果 Bundle extras = data.getExtras(); Bitmap imageBitmap = (Bitmap) extras.get("data"); if (extras != null) { // 检查extras是否为null // Bitmap imageBitmap = (Bitmap) extras.get("data"); if (imageBitmap != null) {// 检查photo是否为null try { String filename = "diary_image_" + System.currentTimeMillis() + ".jpg"; File file = new File(getExternalFilesDir(null), filename); FileOutputStream fos = new FileOutputStream(file); imageBitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos); fos.flush(); fos.close(); imagePath = file.getAbsolutePath(); // 改：ivImage.setImageBitmap(imageBitmap); // 显示图片 // 使用Glide加载图片 GlideEngine engine = GlideEngine.createGlideEngine(); engine.loadImage(this, imagePath, ivImage); } catch (IOException e) { e.printStackTrace(); ivImage.setBackgroundColor(getResources().getColor(android.R.color.darker_gray)); } } } } } private void initView() { // 初始化界面组件 etTitle=findViewById(R.id.etTitle); etContent=findViewById(R.id.etContent); tvDate=findViewById(R.id.tvDate); ivImage=findViewById(R.id.ivImage); btnAddImage=findViewById(R.id.btnAddImage); btnSave=findViewById(R.id.btnSave); btnDelete=findViewById(R.id.btnDelete); dbHelper=new DatabaseHelper(this); // 初始化数据库助手 // userId=getIntent().getIntExtra("userId",-1); // diaryId=getIntent().getIntExtra("diaryId",-1); } } LoginActivity：package com.example.diaryapp; import android.content.Intent; import android.content.SharedPreferences; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Toast; import androidx.activity.EdgeToEdge; import androidx.appcompat.app.AppCompatActivity; import androidx.core.graphics.Insets; import androidx.core.view.ViewCompat; import androidx.core.view.WindowInsetsCompat; import com.example.diaryapp.utils.DatabaseHelper; public class LoginActivity extends AppCompatActivity { private EditText etUsername,etPassword; private CheckBox cbRemember; private DatabaseHelper dbHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); EdgeToEdge.enable(this); setContentView(R.layout.activity_login); // 初始化界面组件 initView(); // 获取SharedPreferences中的保存信息 SharedPreferences prefs=getSharedPreferences("DiaryApp",MODE_PRIVATE); String username=prefs.getString("username",""); String password=prefs.getString("password",""); // 如果用户名存在但密码不存在，删除用户名 if (username.isEmpty() || password.isEmpty()){ prefs.edit().remove("username").remove("password").apply(); } boolean remember=prefs.getBoolean("remember",false); etUsername.setText(username); etPassword.setText(password); cbRemember.setChecked(remember); // 登录按钮监听 Button btnLogin=findViewById(R.id.btnLogin); btnLogin.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { login(); } }); // 注册按钮监听 Button btnRegister=findViewById(R.id.btnRegister); btnRegister.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent=new Intent(LoginActivity.this, RegisterActivity.class); startActivity(intent); } }); } private void login() { String username=etUsername.getText().toString().trim(); String password=etPassword.getText().toString().trim(); boolean remember=cbRemember.isChecked(); // 验证输入 if (username.isEmpty() || password.isEmpty()){ Toast.makeText(this, "用户名和密码不能为空", Toast.LENGTH_SHORT).show(); return; } // 保存登录信息到SharedPreferences SharedPreferences prefs=getSharedPreferences("DiaryApp",MODE_PRIVATE); SharedPreferences.Editor editor=prefs.edit(); // 如果记住密码被勾选，则保存密码；否则清空密码 if (remember){ editor.putString("username",username); editor.putString("password",password); }else { // editor.remove("username"); editor.remove("password"); // 确保未勾选时清空密码 } editor.putBoolean("remember",remember); editor.apply(); // 验证用户 if (dbHelper.checkUser(username,password)){ Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show(); Intent intent=new Intent(LoginActivity.this,MainActivity.class); intent.putExtra("username",username); startActivity(intent); finish(); // 关闭登录界面，避免返回时重复登录 }else { Toast.makeText(this, "用户名或密码错误", Toast.LENGTH_SHORT).show(); } } private void initView() { // 初始化界面组件 etUsername=findViewById(R.id.etUsername); etPassword=findViewById(R.id.etPassword); cbRemember=findViewById(R.id.cbRemember); dbHelper=new DatabaseHelper(this); } }MainActivity：package com.example.diaryapp; import android.annotation.SuppressLint; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; import androidx.activity.EdgeToEdge; import androidx.appcompat.app.AppCompatActivity; import androidx.core.graphics.Insets; import androidx.core.view.ViewCompat; import androidx.core.view.WindowInsetsCompat; import androidx.recyclerview.widget.LinearLayoutManager; import androidx.recyclerview.widget.RecyclerView; import com.example.diaryapp.adapters.DiaryAdapter; import com.example.diaryapp.models.Diary; import com.example.diaryapp.utils.DatabaseHelper; import java.util.ArrayList; import java.util.List; public class MainActivity extends AppCompatActivity { private RecyclerView rvDiaryList; private DiaryAdapter diaryAdapter; private List<Diary> diaryList; private DatabaseHelper dbHelper; private String username; private int userId; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); EdgeToEdge.enable(this); setContentView(R.layout.activity_main); dbHelper=new DatabaseHelper(this); // 获取传递过来的用户名 username=getIntent().getStringExtra("username"); if (username == null){ // 用户名为空，可能是登录流程的问题 Toast.makeText(this, "用户名为空", Toast.LENGTH_SHORT).show(); finish(); return; } userId=dbHelper.getUserId(username); if (userId == -1){ // 用户ID无效，可能是数据库查询的问题 Toast.makeText(this, "用户ID无效", Toast.LENGTH_SHORT).show(); finish(); return; } // 初始化界面组件 initView(); // 加载日记 loadDiaries(); // 添加日记按钮监听 Button btnAddDiary=findViewById(R.id.btnAddDiary); // 在添加日记的按钮点击事件中 btnAddDiary.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent=new Intent(MainActivity.this,DiaryActivity.class); intent.putExtra("userId",userId); startActivityForResult(intent,1); } }); } protected void onActivityResult(int requestCode,int resultCode,Intent data){ super.onActivityResult(requestCode,resultCode,data); if (requestCode == 1 && resultCode == RESULT_OK){ // List<Diary> diaries = dbHelper.getDiariesByUserId(userId); // diaryAdapter.updateDiaries(diaries); //更新适配器数据 loadDiaries(); // 刷新日记列表 } } @SuppressLint("NotifyDataSetChanged") private void loadDiaries() { diaryList.clear(); // 清空当前列表 diaryList.addAll(dbHelper.getDiariesByUserId(userId)); // 从数据库重新获取数据 diaryAdapter.notifyDataSetChanged(); // 通知适配器数据已更改 } private void initView() { rvDiaryList=findViewById(R.id.rvDiaryList); rvDiaryList.setLayoutManager(new LinearLayoutManager(this)); diaryList=new ArrayList<>(); // 确保传递 userId 给 DiaryAdapter diaryAdapter=new DiaryAdapter(this,diaryList,userId); rvDiaryList.setAdapter(diaryAdapter); } }RegisterActivity：package com.example.diaryapp; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import androidx.activity.EdgeToEdge; import androidx.appcompat.app.AppCompatActivity; import androidx.core.graphics.Insets; import androidx.core.view.ViewCompat; import androidx.core.view.WindowInsetsCompat; import com.example.diaryapp.utils.DatabaseHelper; public class RegisterActivity extends AppCompatActivity { private EditText etUsername,etPassword,etConfirmPassword; private Button btnRegister; private DatabaseHelper dbHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); EdgeToEdge.enable(this); setContentView(R.layout.activity_register); // 初始化界面组件 initView(); // 注册按钮监听 btnRegister=findViewById(R.id.btnRegister); btnRegister.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { registerUser(); } }); // 返回登录按钮监听 Button btnBack=findViewById(R.id.btnBack); btnBack.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent=new Intent(RegisterActivity.this, LoginActivity.class); startActivity(intent); } }); } private void registerUser() { String username=etUsername.getText().toString().trim(); String password=etPassword.getText().toString().trim(); String confirmPassword=etConfirmPassword.getText().toString().trim(); // 验证输入 if (username.isEmpty() || password.isEmpty() || confirmPassword.isEmpty()){ Toast.makeText(this, "所有字段不能为空", Toast.LENGTH_SHORT).show(); return; } if (!password.equals(confirmPassword)){ Toast.makeText(this, "两次输入的密码不一致", Toast.LENGTH_SHORT).show(); return; } // 检查用户名是否已被注册 if (dbHelper.checkUser(username,password)){ Toast.makeText(this, "该用户名已被注册", Toast.LENGTH_SHORT).show(); return; } // 注册新用户 long result=dbHelper.addUser(username,password); if (result > 0){ Toast.makeText(this, "注册成功", Toast.LENGTH_SHORT).show(); Intent intent=new Intent(RegisterActivity.this,LoginActivity.class); startActivity(intent); finish(); }else { Toast.makeText(this, "注册失败", Toast.LENGTH_SHORT).show(); } } private void initView() { etUsername=findViewById(R.id.etUsername); etPassword=findViewById(R.id.etPassword); etConfirmPassword=findViewById(R.id.etConfirmPassword); dbHelper=new DatabaseHelper(this); } }
06-06
if(activity==null||activity.isFinishing())return;activity.diaryList.clear();activity.diaryList.addAll(diaries);activity.diaryAdapter.notifyDataSetChanged();//注意：这里不能关闭dbHelper，因为我们在...
【Android入门】5、Broadcast 广播、Kotlin 的高阶函数、泛型、委托
呆呆的猫的博客
09-25 562
广播用于在Android系统内实现通知,概念较为简单为了实现上述效果, 代码如下receiverreceiveractivities其中注册和反注册, 是写在onResume和onPause内, 而不是onCreate和onDestroy, 是因为我们希望只有栈顶的activity才可收到强制下线的广播, 其他非栈顶的activity不应该且没必要收此广播, 即当一个activity失去栈顶位置时自动取消的注册buttonbroadcast主activity
package com.chinaiatb.mrdoctor.utils; import android.Manifest; import android.app.Activity; import android.content.ActivityNotFoundException; import android.content.ContentResolver; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.content.pm.ResolveInfo; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.PixelFormat; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.os.Environment; import android.os.Handler; import android.provider.MediaStore; import androidx.annotation.NonNull; import androidx.core.content.FileProvider; import android.provider.OpenableColumns; import android.provider.Settings; import android.text.TextUtils; import android.util.Log; import android.view.Gravity; import android.view.View; import android.view.WindowManager; import android.webkit.MimeTypeMap; import android.widget.TextView; import android.widget.Toast; import com.blankj.utilcode.util.LogUtils; import com.chinaiatb.mrdoctor.R; import com.chinaiatb.mrdoctor.base.ui.widget.ActionSheetDialog; import com.chinaiatb.mrdoctor.base.utils.FileUtils; import com.chinaiatb.mrdoctor.base.utils.PermissionUtils; import com.chinaiatb.mrdoctor.base.utils.ToastUtil; import com.chinaiatb.mrdoctor.configs.GlobalConstant; import com.chinaiatb.mrdoctor.configs.ParamsConfigs; import com.chinaiatb.mrdoctor.ui.test.friend.view.SelectImageActivity; import com.chinaiatb.mrdoctor.ui.test.model.Image; import com.google.android.material.snackbar.Snackbar; import com.huawei.hms.utils.IOUtils; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Locale; import static com.blankj.utilcode.util.StringUtils.getString; import static com.chinaiatb.mrdoctor.configs.IntentParameter.TAG; /** * description: * 2020/12/10. * auth:lihe */ public class AddPictureFileUtils { private ActionSheetDialog sheetDialog; private Activity mActivity; public AddPictureFileUtils(Activity activity, int singleOrMulti, boolean needCrop){ this.mActivity = activity; this.singleOrMulti = singleOrMulti; if(needCrop){ FILE_SAVEPATH = getSDPath(mActivity.getBaseContext()); // SELECT_FILE_SAVEPATH = getSDPath(mActivity.getBaseContext()); TEMP_DIR_PATH = ParamsConfigs.TEMP_SAVE_PATH_11; } } public AddPictureFileUtils(Activity activity, int singleOrMulti){ this.mActivity = activity; this.singleOrMulti = singleOrMulti; } private final static String AUTHORITY_NAME = "com.chinaiatb.mrdoctor.fileprovider"; private String FILE_SAVEPATH = ParamsConfigs.PICTURE_SAVE_PATH; private String TEMP_DIR_PATH = ParamsConfigs.TEMP_SAVE_PATH; private String SELECT_FILE_SAVEPATH = ParamsConfigs.SELECT_FILE_SAVE_PATH; private String FileFlag; private Uri origUri;//原始uri private Uri cropUri;//剪裁后的uri private Uri selectFileUri; private File uploadPicFile;//上传照片 private String uploadPicPath;//上传照片路径 private File uploadSelectFile;//上传文件 private String uploadSelectFilePath;//上传文件路径 private List<String> selectedFileNames = new ArrayList<>(); private File uploadOriPicFile;//原始照片 private String uploadOriPicPath;//原始照片路径 private String fileType; private boolean needCutPicture;//标记是否需要剪裁 private int singleOrMulti = SINGLE_CHOOSE;//标记单选还是多选 public static final int SINGLE_CHOOSE = 1;//照片单选f public static final int MULTI_CHOOSE = 2;//照片多选 /** 请求相册 */ public static final int REQUEST_CODE_GETIMAGE_BYSDCARD = 0; /** 请求相机 */ public static final int REQUEST_CODE_GETIMAGE_BYCAMERA = 1; /** 请求裁剪 */ public static final int REQUEST_CODE_GETIMAGE_BYCROP = 2; /** 请求文件 */ public static final int REQUEST_CODE_GETFILE = 3; private final int CROP = 200; /** 请求存储权限 */ private static final int REQUEST_CODE_STORAGE_PERMISSION = 4; /** * 检查相机存储权限 */ public void checkPremission(boolean needCutPicture,String fileFlag) { FileFlag = fileFlag; this.needCutPicture = needCutPicture; CharSequence[] items = { getString(R.string.str_img_from_camera), getString(R.string.str_img_from_album) }; imageChooseItem(items); } /* * 获取SDK=30及以上的存储路径 * */ public static String getSDPath(Context context) { File sdDir = null; boolean sdCardExist = Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED);// 判断sd卡是否存在 if (sdCardExist) { if (Build.VERSION.SDK_INT>=29){ //Android10之后 sdDir = context.getExternalFilesDir(null); }else { sdDir = Environment.getExternalStorageDirectory();// 获取SD卡根目录 } } else { sdDir = Environment.getRootDirectory();// 获取跟目录 } return sdDir.toString(); } public void checkCameraPermissions(){ String[] permissions = new String[]{ // Manifest.permission.WRITE_EXTERNAL_STORAGE, // Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA}; //这里的this不是上下文，是Activity对象！ PermissionUtils.getInstance().chekPermissions(mActivity, permissions, permissionsCameraResult,1); // ToastUtil.showLongToastTop("用于扫码登录、扫码签名、患者问题答复时添加图片或视频信息"); } //创建监听权限的接口对象 PermissionUtils.IPermissionsResult permissionsCameraResult = new PermissionUtils.IPermissionsResult() { @Override public void passPermissons() { onSheetDialogClick(1); } @Override public void forbitPermissons() { ToastUtil.showShortToast("没有权限!"); } }; public void checkFilePermissions(){ String[] permissions = new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE, }; //这里的this不是上下文，是Activity对象！ PermissionUtils.getInstance().chekPermissions(mActivity, permissions, permissionsFileResult,1); } PermissionUtils.IPermissionsResult permissionsFileResult = new PermissionUtils.IPermissionsResult() { @Override public void passPermissons() { onSheetDialogClick(2); } @Override public void forbitPermissons() { ToastUtil.showShortToast("没有权限!"); } }; public void checkAlbumPermissions(){ String[] permissions = new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE, }; //这里的this不是上下文，是Activity对象！ PermissionUtils.getInstance().chekPermissions(mActivity, permissions, permissionsAlbumResult,1); } //创建监听权限的接口对象 PermissionUtils.IPermissionsResult permissionsAlbumResult = new PermissionUtils.IPermissionsResult() { @Override public void passPermissons() { onSheetDialogClick(0); } @Override public void forbitPermissons() { ToastUtil.showShortToast("没有权限!"); } }; public void initDialog(){ if(null != sheetDialog){ return; } sheetDialog = new ActionSheetDialog(mActivity).builder(); sheetDialog.addSheetItem(getString(R.string.str_img_from_camera), null, new ActionSheetDialog.OnSheetItemClickListener() { @Override public void onClick(int which) { if(GlobalConstant.isAtRoomActivity){//还在视频过程中，不能拍照 ToastUtil.showShortToast("视频通话中，无法使用此功能"); }else{ checkCameraPermissions(); } } }); sheetDialog.addSheetItem(getString(R.string.str_img_from_album), null, new ActionSheetDialog.OnSheetItemClickListener() { @Override public void onClick(int which) { checkAlbumPermissions(); } }); //if (FileFlag=="1"){ if ("1".equals(FileFlag)){ sheetDialog.addSheetItem(getString(R.string.str_file_select), null, new ActionSheetDialog.OnSheetItemClickListener() { @Override public void onClick(int which) { checkFilePermissions(); } });} } /** * 相机选择和拍照 * @param items */ private void imageChooseItem(CharSequence[] items) { mActivity.runOnUiThread(new Runnable() { @Override public void run() { initDialog(); if (mActivity == null || mActivity.isDestroyed() || mActivity.isFinishing()) { return; } sheetDialog.show(); } }); } private void onSheetDialogClick(int position){ //判断是否挂载了SD卡 String storageState = Environment.getExternalStorageState(); if(storageState.equals(Environment.MEDIA_MOUNTED)){ File savedir = new File(FILE_SAVEPATH); File tempdir = new File(TEMP_DIR_PATH); if (!savedir.exists()) { savedir.mkdirs(); } if (!tempdir.exists()) { tempdir.mkdirs(); } } else{ ToastUtil.showShortToast("SD卡未挂载,不能操作照片"); return; } //输出裁剪的临时文件 String timeStamp = new SimpleDateFormat("yyyyMMddHHmmss", Locale.getDefault()).format(new Date()); //照片命名 String origFileName = "byt_" + timeStamp + ".jpg"; String cropFileName = "byt_crop_" + timeStamp + ".jpg"; uploadOriPicPath = FILE_SAVEPATH + origFileName; uploadOriPicFile = new File(uploadOriPicPath); //裁剪头像的绝对路径 uploadPicPath = FILE_SAVEPATH + cropFileName; uploadPicFile = new File(uploadPicPath); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { origUri = FileProvider.getUriForFile(mActivity, AUTHORITY_NAME, uploadOriPicFile); }else{ origUri = Uri.fromFile(uploadOriPicFile); } cropUri = Uri.fromFile(uploadPicFile); //相册选图 if(position == 0) { if(singleOrMulti == SINGLE_CHOOSE){ startImagePick(); }else{ startActivity(); } } //手机拍照 else if(position == 1){ startActionCamera(); } //文件管理 else if(position == 2) { startActionFile(); } } private ArrayList<Image> mSelectImages = new ArrayList<>(); public static final int SELECT_IMAGE_REQUEST = 0x0011; private void startActivity() { Intent intent = new Intent(mActivity, SelectImageActivity.class); intent.putParcelableArrayListExtra("selected_images", mSelectImages); mActivity.startActivityForResult(intent, SELECT_IMAGE_REQUEST); } /** * 选择图片并直接裁剪 */ private void startImagePick() { // // 检查权限是否已授予 // if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { // if (!Environment.isExternalStorageManager()) { // // 如果没有权限，打开设置页面让用户授予权限 // Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION); // mActivity.startActivityForResult(intent, REQUEST_CODE_STORAGE_PERMISSION); // return; // } // } // // 否则，执行正常的图片选择操作 Intent intent = new Intent(Intent.ACTION_PICK,null); intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*"); mActivity.startActivityForResult(Intent.createChooser(intent, "选择图片"),REQUEST_CODE_GETIMAGE_BYSDCARD); } /** * 相机拍照 */ private void startActionCamera() { Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); intent.putExtra(MediaStore.EXTRA_OUTPUT, selectFileUri/*this.getCameraTempFile()*/); // 添加这一句表示对目标应用临时授权该Uri所代表的文件 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION); } mActivity.startActivityForResult(intent, REQUEST_CODE_GETIMAGE_BYCAMERA); } private void startActionFile() { Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType("application/pdf,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document,application/vnd.ms-excel,application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"); intent.addCategory(Intent.CATEGORY_OPENABLE); // 添加可打开的文件分类 mActivity.startActivityForResult(Intent.createChooser(intent, "选择文件"), REQUEST_CODE_GETFILE); } /** * 拍照后裁剪 * @param data 原始图片 */ private void startActionCrop(Uri data, boolean fromCamera) { Intent intent = new Intent("com.android.camera.action.CROP"); intent.setDataAndType(data, "image/*"); if (fromCamera && Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION); } intent.putExtra("return-data", false); intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1);// 裁剪框比例 intent.putExtra("aspectY", 1); intent.putExtra("outputX", CROP); intent.putExtra("outputY", CROP); intent.putExtra("scale", true); intent.putExtra("scaleUpIfNeeded", true);// 去黑边 intent.putExtra(MediaStore.EXTRA_OUTPUT, cropUri); mActivity.startActivityForResult(intent, REQUEST_CODE_GETIMAGE_BYCROP); } private void startActionCrop2(File targetPhoto) { Intent intent = new Intent("com.android.camera.action.CROP"); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { // intent.setAction(Intent.ACTION_OPEN_DOCUMENT); intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION); intent.setDataAndType(getUriByFileForN(targetPhoto), "image/*"); }else{ intent.setDataAndType(Uri.fromFile(targetPhoto), "image/*"); } intent.putExtra(MediaStore.EXTRA_OUTPUT, cropUri); intent.putExtra("return-data", false); intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1);// 裁剪框比例 intent.putExtra("aspectY", 1); intent.putExtra("outputX", CROP); intent.putExtra("outputY", CROP); intent.putExtra("scale", true); intent.putExtra("scaleUpIfNeeded", true);// 去黑边 mActivity.startActivityForResult(intent, REQUEST_CODE_GETIMAGE_BYCROP); } private void startActionCrop3(Uri sourceUri) { uploadPicFile = FileUtils.createImageFile(mActivity.getApplication(), true); Intent intent = new Intent("com.android.camera.action.CROP"); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { // Android N 及以上版本，确保裁剪图片时可以访问文件 intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION); intent.setDataAndType(sourceUri, "image/*"); } // 设置裁剪输出文件的路径，针对不同版本需要做不同的处理 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { // Android 10 及以上版本，需要通过 FileProvider 获取 content:// URI intent.putExtra(MediaStore.EXTRA_OUTPUT, FileUtils.uri); // FileUtils.uri 是通过 FileProvider 提供的 URI } else { // 对于 Android 9 以下版本，使用 Uri.fromFile 来处理 file:// URI Uri imgCropUri = Uri.fromFile(uploadPicFile); intent.putExtra(MediaStore.EXTRA_OUTPUT, imgCropUri); } //intent.putExtra("return-data", true); // 设置为 true 来返回裁剪数据 // 设置裁剪的相关参数 intent.putExtra("return-data", false); // 不返回裁剪数据，返回文件 URI intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1); // 裁剪框的比例 intent.putExtra("aspectY", 1); intent.putExtra("outputX", CROP); // 裁剪后的宽度 intent.putExtra("outputY", CROP); // 裁剪后的高度 intent.putExtra("scale", true); // 允许缩放 intent.putExtra("scaleUpIfNeeded", true); // 去掉黑边 Log.d("yyyyy4", "needCutPicture="); mActivity.startActivityForResult(intent, REQUEST_CODE_GETIMAGE_BYCROP); } private Uri getImageContentUri(File imageFile){ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { String filePath = imageFile.getAbsolutePath(); Cursor cursor = mActivity.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[]{MediaStore.Images.Media._ID}, MediaStore.Images.Media.DATA + "=? ", new String[]{filePath}, null); try { if (cursor != null && cursor.moveToFirst()) { int id = cursor.getInt(cursor.getColumnIndex(MediaStore.MediaColumns._ID)); Uri baseUri = Uri.parse("content://media/external/images/media"); return Uri.withAppendedPath(baseUri, "" + id); } else { if (imageFile.exists()) { Uri tempUri = null; if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { tempUri = FileProvider.getUriForFile(mActivity, AUTHORITY_NAME, imageFile); }else{ tempUri = Uri.fromFile(imageFile); } return tempUri; } } }catch(Exception e){ e.printStackTrace(); } finally { if (cursor != null) { cursor.close(); } } } else { return Uri.fromFile(imageFile); } return null; } /** * Android7.0根据文件获取uri */ private Uri getUriByFileForN( File imageFile) { String filePath = imageFile.getAbsolutePath(); Cursor cursor = mActivity.getContentResolver().query( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[]{MediaStore.Images.Media._ID}, MediaStore.Images.Media.DATA + "=? ", new String[]{filePath}, null); if (cursor != null && cursor.moveToFirst()) { int id = cursor.getInt(cursor .getColumnIndex(MediaStore.MediaColumns._ID)); Uri baseUri = Uri.parse("content://media/external/images/media"); return Uri.withAppendedPath(baseUri, "" + id); } else { Uri tempUri = null; if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { tempUri = FileProvider.getUriForFile(mActivity, AUTHORITY_NAME, imageFile); }else{ tempUri = Uri.fromFile(imageFile); } return tempUri; } } /*************************************************************************/ /** * 选择相册图片时保存临时图片并获取图片临时路径 * @param data * @return */ private String getPhotoPathByUri(Intent data) { Uri contentUri = data.getData(); //copy file and send new file path String fileName = getFileName(contentUri); if (!TextUtils.isEmpty(fileName)) { File copyFile = new File(TEMP_DIR_PATH + File.separator + fileName); copy(contentUri, copyFile); return copyFile.getAbsolutePath(); } return null; } public String getFileName(Uri uri) { if (uri == null) return null; String fileName = null; String path = uri.getPath(); int cut = path.lastIndexOf('/'); if (cut != -1) { fileName = path.substring(cut + 1); } return fileName; } public void copy( Uri srcUri, File dstFile) { try { InputStream inputStream = mActivity.getContentResolver().openInputStream(srcUri); if (inputStream == null) return; OutputStream outputStream = new FileOutputStream(dstFile); IOUtils.copy(inputStream, outputStream); inputStream.close(); outputStream.close(); } catch (Exception e) { e.printStackTrace(); } } private String saveSelectedFile(Uri srcUri) { String fileName = getFileName(srcUri); if (!TextUtils.isEmpty(fileName)) { File copyFile = new File(TEMP_DIR_PATH + File.separator + fileName); copy(srcUri, copyFile); return copyFile.getAbsolutePath(); } return null; } /*************************************************************************/ public String getUploadPicPath(){ return uploadPicPath; } public void setUploadPicPath(String uploadPicPath){ this.uploadPicPath = uploadPicPath; } public String getUploadOriPicPath(){ return uploadOriPicPath; } public void setUploadOriPicPath(String uploadOriPicPath){ this.uploadOriPicPath = uploadOriPicPath; } public String getUploadSelectFilePath(){ return uploadSelectFilePath; } public void setUploadSelectFilePath(String uploadSelectFilePath){ this.uploadSelectFilePath = uploadSelectFilePath; } public void dealOnActivityResult(int requestCode, int resultCode, Intent data,String AddFileFlag){ createFile(); Log.d("yyyyy0", "deal"); switch(requestCode) { case AddPictureFileUtils.REQUEST_CODE_GETIMAGE_BYCAMERA://拍照后的返回 if(!uploadOriPicFile.exists()) { //htc等手机可能存储在别的地方 Bitmap cameraBitMapData; if (data != null && data.hasExtra("data")) {//Intent带出 cameraBitMapData = data.getParcelableExtra("data"); } else { //存在系统路径 //获取系统拍照图片文件夹 Uri uri_DCIM = null; if (data.getData() != null) { uri_DCIM = data.getData(); } else { uri_DCIM = MediaStore.Images.Media.EXTERNAL_CONTENT_URI; } String DCIMPath = ""; //本次照片绝对路径 Cursor cr = mActivity.getContentResolver().query(uri_DCIM, new String[]{MediaStore.Images.Media.DATA}, null, null, MediaStore.Images.Media.DATE_MODIFIED + " desc");//降序排找最新的 if (cr.moveToFirst()) { DCIMPath = cr.getString(cr.getColumnIndex(MediaStore.Images.Media.DATA)); } cr.close(); cameraBitMapData = BitmapFactory.decodeFile(DCIMPath); } try { uploadOriPicFile.createNewFile(); //创建文件 FileOutputStream fos = new FileOutputStream(uploadOriPicFile); cameraBitMapData.compress(Bitmap.CompressFormat.JPEG, 100, fos); fos.flush(); fos.close(); } catch (IOException e) { LogUtils.w("=拍照图片保存发生异常!" + e); } } if(needCutPicture){ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { try { startActionCrop3(getImageContentUri(uploadOriPicFile)); } catch (Exception e) { e.printStackTrace(); } } else { startActionCrop(getImageContentUri(uploadOriPicFile), true);//拍照后裁剪 } }else{ uplodTakePhotoFile(); } break; case AddPictureFileUtils.REQUEST_CODE_GETIMAGE_BYSDCARD://相册选择后的返回 Uri pickUri = data.getData(); Log.d("yyyyy", "pickUri: "+pickUri+"pickUri.getPath()"+pickUri.getPath()+"needCutPicture="+needCutPicture); if(pickUri != null && pickUri.getPath() != null){ if(needCutPicture){ Log.d("yyyyy1", "needCutPicture="+needCutPicture); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { try { Log.d("yyyyy2", "needCutPicture="+needCutPicture); //Uri fileUri = Uri.fromFile(new File(filePath)); Uri fileUri = FileProvider.getUriForFile(mActivity, "com.chinaiatb.mrdoctor.fileprovider", new File(getPhotoPathByUri(data))); //startActionCrop3(pickUri); startActionCrop3(fileUri); //startActionCrop2(new File(getPhotoPathByUri(data)));// 选图后裁剪 }catch (Exception e){ Log.d("yyyyy3", "needCutPicture="+needCutPicture); e.printStackTrace(); } }else{ startActionCrop2(new File(getPhotoPathByUri(data)));// 选图后裁剪 } }else{ uploadPhotoAlbumFile(data); } }else{ ToastUtil.showShortToast(getString(R.string.str_selected_pic_err)); } break; case AddPictureFileUtils.REQUEST_CODE_GETFILE: Uri pickFileUri = data.getData(); if (pickFileUri != null && pickFileUri.getPath() != null) { uploadSelectFilePath = getFilePathFromUri(mActivity.getApplicationContext(), pickFileUri); Log.d(TAG, "dealOnActivityResult: "+uploadSelectFilePath); fileType = getFileMimeType(mActivity.getApplicationContext(), pickFileUri); uploadSelectFile = new File(uploadSelectFilePath); 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android.app.role.MUSIC不存在
06-26
<think>我们正在解决一个Android开发问题：用户报告`android.app.role.MUSIC`不存在。我们需要分析原因并提供解决方案。首先，我们需要明确：在Android框架中，角色（Role）系统是在Android10（API级别29）引入的。角色（如`ROLE_MUSIC`）是预定义的字符串常量，用于管理特定类型的应用程序（例如音乐播放器、浏览器等）。这些角色常量定义在`android.app.role`包中。但是，用户提到的`android.app.role.MUSIC`并不存在。实际上，正确的角色名称应该是`ROLE_MUSIC`，它是一个字符串常量，而不是一个类。因此，用户可能误解了使用方式。在Android中，角色常量是`RoleManager`类中的字符串常量。例如，音乐播放器角色的常量是`RoleManager.ROLE_MUSIC`（从Android10开始）。可能的原因：1.**API级别过低**：如果应用的目标API级别低于29（Android10），则无法使用`RoleManager`中的角色常量，因为它们在Android10中引入。2.**错误的引用**：用户可能错误地引用了`android.app.role.MUSIC`，而正确的引用应该是`android.app.role.RoleManager.ROLE_MUSIC`（或者直接使用字符串"android.app.role.MUSIC"，但官方推荐使用常量）。3.**拼写错误或错误使用**：可能用户将常量名写错了，或者尝试以类的方式使用它（而它实际上是一个字符串常量）。解决方案：1.**检查API级别**：确保应用的目标API级别至少为29（Android10）或更高。在`build.gradle`文件中设置：```groovyandroid{compileSdkVersion29//或更高defaultConfig{minSdkVersion...//但使用RoleManager需要minSdkVersion至少为29，或者进行运行时检查targetSdkVersion29//或更高}}```注意：如果应用需要支持低于29的版本，则需要在运行时检查。2.**正确使用角色常量**：应该使用`RoleManager`类中定义的常量。例如：```javaif(Build.VERSION.SDK_INT>=Build.VERSION_CODES.Q){RoleManagerroleManager=(RoleManager)getSystemService(ROLE_SERVICE);if(roleManager.isRoleAvailable(RoleManager.ROLE_MUSIC)){//请求角色Intentintent=roleManager.createRequestRoleIntent(RoleManager.ROLE_MUSIC);startActivityForResult(intent,REQUEST_CODE);}}```或者，如果使用Kotlin：```kotlinif(Build.VERSION.SDK_INT>=Build.VERSION_CODES.Q){valroleManager=getSystemService(RoleManager::class.java)if(roleManager.isRoleAvailable(RoleManager.ROLE_MUSIC)){valintent=roleManager.createRequestRoleIntent(RoleManager.ROLE_MUSIC)startActivityForResult(intent,REQUEST_CODE)}}```3.**使用字符串常量**：如果由于某种原因无法使用`RoleManager.ROLE_MUSIC`（例如在低于API29的版本上编译但又在运行时检查），可以直接使用字符串字面值：```javaStringroleMusic="android.app.role.MUSIC";```但请注意，直接使用字符串容易出错，所以推荐使用常量。4.**处理低版本兼容**：在低于Android10的设备上，角色系统不可用，因此需要提供备用方案。例如，对于音乐播放器，可能需要使用传统的媒体按钮广播接收器。5.**检查权限**：请求角色不需要特殊权限，但需要启动一个活动让用户授予该角色。总结：用户遇到的问题很可能是因为错误的常量引用（`android.app.role.MUSIC`）或API级别过低。正确的常量是`RoleManager.ROLE_MUSIC`，并且需要确保在Android10及以上设备使用。最后，生成相关问题：§§相关问题§§1.如何在Android10及以上版本中请求成为默认音乐播放器？2.如何兼容Android10以下版本设置默认音乐播放器？3.如何检查当前应用是否已获得特定角色（如音乐播放器）？4.`RoleManager`类中还有哪些预定义的角色？</think>### Android `android.app.role.MUSIC` 不存在的原因及解决方案 #### 原因分析 1. **API 级别限制** `RoleManager` 及相关角色常量（如 `ROLE_MUSIC`）仅在 **Android 10（API 级别 29）及以上**引入。若应用运行在低版本系统（如 Android 9）或未正确设置 `minSdkVersion`，将无法访问这些类[^1]。 2. **错误引用方式** `MUSIC` 是 `RoleManager` 类中的常量，而非独立类。正确引用应为： ```java RoleManager.ROLE_MUSIC // 正确格式 ``` 错误写法 `android.app.role.MUSIC` 会导致类未找到异常。 3. **包名混淆** `RoleManager` 属于 `android.app.role` 包，但常量定义在 `RoleManager` 内部。混淆包路径会导致引用失败。 4. **编译配置问题** - 未在 `build.gradle` 中声明 `minSdkVersion >= 29` - 未导入正确包：`import android.app.role.RoleManager;` --- #### 解决方案 ##### 1. 正确引用角色常量 ```java // Kotlin 示例 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) { val roleManager = getSystemService(RoleManager::class.java) val isMusicRoleAvailable = roleManager.isRoleAvailable(RoleManager.ROLE_MUSIC) if (isMusicRoleAvailable) { val intent = roleManager.createRequestRoleIntent(RoleManager.ROLE_MUSIC) startActivityForResult(intent, REQUEST_CODE) } } ``` ##### 2. 兼容低版本系统 ```java // 版本兼容处理 public static void requestMusicRole(Activity activity) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) { RoleManager roleManager = (RoleManager) activity.getSystemService(ROLE_SERVICE); if (roleManager.isRoleAvailable(RoleManager.ROLE_MUSIC)) { activity.startActivityForResult( roleManager.createRequestRoleIntent(RoleManager.ROLE_MUSIC), REQUEST_CODE ); } } else { // Android 9及以下：使用隐式Intent Intent intent = new Intent("android.intent.action.MUSIC_PLAYER"); activity.startActivity(intent); } } ``` ##### 3. 配置 Gradle 确保 `app/build.gradle` 包含： ```groovy android { defaultConfig { minSdkVersion 29 // 最低支持 Android 10 targetSdkVersion 34 } } ``` ##### 4. 检查权限 在 `AndroidManifest.xml` 中添加必要权限： ```xml <uses-permission android:name="android.permission.MANAGE_ROLE_HOLDERS" /> ``` ##### 5. 验证角色可用性 ```java if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) { RoleManager roleManager = (RoleManager) getSystemService(ROLE_SERVICE); // 检查设备是否支持音乐角色 boolean isSupported = roleManager.isRoleAvailable(RoleManager.ROLE_MUSIC); } ``` --- #### 关键注意事项 - **运行时检查**：始终用 `Build.VERSION.SDK_INT` 包裹角色相关代码。 - **常量值**：`ROLE_MUSIC` 实际值为字符串 `"android.app.role.MUSIC"`，但**禁止直接使用字符串**，必须通过常量引用。 - **用户交互**：请求角色会触发系统弹窗，需在 `onActivityResult()` 处理授权结果。 - 替代方案：低版本系统需通过 `MediaSession` 和 `AudioManager` 实现音乐控制[^2]。 ---
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