[Android]-运行手机多媒体-优快云博客

本文链接：https://blog.youkuaiyun.com/renboyu010214/article/details/106896745

本文详细介绍Android中通知(Notification)的创建与定制方法，包括在不同组件中使用通知，以及如何设置声音、震动和灯光等高级特性。同时，文章还介绍了如何在Android应用中集成相机、相册功能，以及播放音频和视频的实现方式。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

使用通知（Notification）

通知的用法相对灵活，可以在活动里创建，也可以在广播接收器里创建，或是在服务里创建，以后两者居多

package cn.ywrby.notificationtest;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.View;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.core.app.NotificationCompat;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button send_notice=findViewById(R.id.bt_notification);
        send_notice.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.bt_notification:
                //Intent与PendingIntent十分类似，不过从实际使用的角度，Intent更强调立即执行
                //PendingIntent更加倾向于在某个合适的时机执行动作
                //PendingIntent的获取方式就是通过PendingIntent的静态方法getActivity，getBroadcast,getService来获取
                //第一个参数依旧是Context，第二个一般设为0，第三个传入Intent对象，第四个用于确定PendingIntent行为，通常传入0
                Intent intent=new Intent(this,NotificationActivity.class);
                PendingIntent pendingIntent=PendingIntent.getActivity(this,0,intent,0);
                NotificationManager manager=(NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                Notification notification=new NotificationCompat.Builder(this,"1")
                        .setContentTitle("This is content title")
                        .setContentText("This is content text")
                        .setWhen(System.currentTimeMillis())
                        .setSmallIcon(R.drawable.notice)
                        .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.drawable.title))
                        .setContentIntent(pendingIntent)  //setContentIntent接收的参数正是一个pendingIntent类型，当用户点击时，执行相关的逻辑
                        //.setAutoCancel(true)  //自动关闭通知栏（点击之后），还可以显式调用NotificationManager的cancle方法将其取消
                        .build();
                manager.notify(1,notification);
                break;
            default:
                break;
        }
    }
}

package cn.ywrby.notificationtest;

import android.app.NotificationManager;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;

public class NotificationActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.notification_layout);
        //显式调用方法将其取消
        NotificationManager manager=(NotificationManager)getSystemService(NOTIFICATION_SERVICE);
        manager.cancel(1);   //这里的1是一开始为这条通知设置的ID
    }
}

通知的进阶技巧

.setSound(Uri.fromFile(new File("/system/media/audio/ringtones/Tuba.ogg")))  //在通知发出时播放一段音频
.setVibrate(new long[] {0,1000,1000,1000})  //设置震动并配置相关系数
.setLights(Color.GREEN,1000,1000)  //设置呼吸灯参数

.setDefaults(NotificationCompat.DEFAULT_ALL) //直接使用系统默认的通知效果

.setPriority(NotificationCompat.PRIORITY_MAX)  //重要程度设置为最高，会立刻显示在屏幕上方，谨慎使用
.setStyle(new NotificationCompat.BigTextStyle().bigText("9月18日，华为全联接2019（HUAWEI CONNECT）大会上，华为副董事长胡厚崑发布了Atlas " +
        "900 AI训练集群，以超强算力带给企业人工智能业务的极致体验。世界正从数字化向智能化转型，人工智能产业作为关键驱动力，面临自身的升级进化的挑战。" +
        "华为在超强人工智能算力和大规模分布式AI训练集群两个方面加速智能化世界的转型。"))   //利用setStyle的BigTextStyle显式长文字内容
.setStyle(new NotificationCompat.BigPictureStyle().bigPicture
        (BitmapFactory.decodeResource(getResources(),R.drawable.photo)))  //通知栏显式大图

在模拟器上正常运行，在华为mate7上文字无法显式，设置图片导致应用闪退，立即通知功能需要手动开启

调用摄像头或相册

package cn.ywrby.cameraalbumtest;

import android.Manifest;
import android.annotation.TargetApi;
import android.content.ContentUris;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.core.content.FileProvider;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.annotation.Target;

public class MainActivity extends AppCompatActivity {

    public static final int TAKE_PHOTO=1;
    public static final int CHOOSE_PHOTO=2;
    private ImageView picture;
    private Uri imageUri;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button takePhoto=findViewById(R.id.bt_takephoto);
        picture=findViewById(R.id.iv_picture);
        takePhoto.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //创建File对象，用于存储拍摄后的图像文件
                //getExternalCacheDir方法可以获取应用的关联缓存目录，将文件保存到这个目录不需要进行权限的申请
                File outputImage=new File(getExternalCacheDir(),"output_image.jpg");
                try{
                    //删除可能存在的之前缓存的文件
                    if(outputImage.exists()){
                        outputImage.delete();
                    }
                    //创建新的图像文件
                    outputImage.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                //由于Android版本不同，这里采用两种不同的方法将File对象转换成Uri对象来标记图片位置
                if(Build.VERSION.SDK_INT>=24){
                    imageUri= FileProvider.getUriForFile(MainActivity.this,"cn.ywrby.cameraalbumtest.fileprovider",outputImage);
                }else {
                    imageUri=Uri.fromFile(outputImage);
                }
                //开启拍摄活动
                Intent intent=new Intent("android.media.action.IMAGE_CAPTURE");
                intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);
                startActivityForResult(intent,TAKE_PHOTO);
            }
        });

        //开启相册
        Button choosePhoto=findViewById(R.id.bt_choosephoto);
        choosePhoto.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //判断是否获得相关权限并获取 
                if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!=PackageManager.PERMISSION_GRANTED){
                    ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
                }else{
                    openAlbum();
                }
            }
        });
    }

    //startActivityForResult拍摄结果返回到onActivityResult方法
    //之后再利用onActivityResult方法将这张图片显示在控件上
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        switch (requestCode){
            //拍照
            case TAKE_PHOTO:
                if(resultCode==RESULT_OK){
                    try{
                        //将图片解析成Bitmap对象，放置到ImageView中
                        Bitmap bitmap= BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                        picture.setImageBitmap(bitmap);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
                break;
            //选择相片  
            case CHOOSE_PHOTO:
                 if(resultCode==RESULT_OK){
                     if(Build.VERSION.SDK_INT>=19){
                         handleImageOnKitKat(data);
                     }else {
                         handleImageBeforeKitKat(data);
                     }
                 }
            default:
                break;
        }
    }

    //打开相册动作
    private void openAlbum(){
        Intent intent=new Intent("android.intent.action.GET_CONTENT");
        intent.setType("image/*");
        startActivityForResult(intent,CHOOSE_PHOTO);
    }

    //获取请求权限结果
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                if(grantResults.length>0 && grantResults[0]== PackageManager.PERMISSION_GRANTED){
                    openAlbum();
                }else {
                    Toast.makeText(this,"you denied the permission!",Toast.LENGTH_SHORT).show();
                }
                break;
            default:
        }
    }

    //针对Android4.4以上版本解析数据
    @TargetApi(19)
    private void handleImageOnKitKat(Intent data){
        String imagePath=null;
        Uri uri=data.getData();
        if(DocumentsContract.isDocumentUri(this,uri)){
            String docID=DocumentsContract.getDocumentId(uri);
            if("com.android.providers.media.documents".equals(uri.getAuthority())){
                String id=docID.split(":")[1];
                String selection=MediaStore.Images.Media._ID+"="+id;
                imagePath=getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,selection);
            }else if("com.android.providers.downloads.documents".equals(uri.getAuthority())){
                Uri contentUri= ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"),Long.valueOf(docID));
                imagePath=getImagePath(contentUri,null);
            }
        }else if("content".equalsIgnoreCase(uri.getScheme())){
            imagePath=getImagePath(uri,null);
        }else if("file".equalsIgnoreCase(uri.getScheme())){
            imagePath=uri.getPath();
        }
        displayImage(imagePath);
    }

    //针对Android4.4之前的版本
    private void handleImageBeforeKitKat(Intent data){
        Uri uri=data.getData();
        String imagePath=getImagePath(uri,null);
        displayImage(imagePath);
    }

    //获取图像路径
    private String getImagePath(Uri uri,String selection){
        String path=null;
        Cursor cursor=getContentResolver().query(uri,null,selection,null,null);
        if(cursor!=null){
            if(cursor.moveToNext()){
                path=cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
            }
            cursor.close();
        }
        return path;
    }


    //摆放图片至控件处
    private void displayImage(String imagePath){
        if(imagePath!=null){
            Bitmap bitmap=BitmapFactory.decodeFile(imagePath);
            picture.setImageBitmap(bitmap);
        }else {
            Toast.makeText(this,"failed to get image!",Toast.LENGTH_SHORT).show();
        }
    }
}

播放多媒体文件

播放音频

主要涉及的就是MediaPlayer的使用

package cn.ywrby.mediaplayertest;

import android.Manifest;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.os.Build;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import java.io.File;
import java.io.IOException;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private MediaPlayer mediaPlayer=new MediaPlayer();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bt_play=findViewById(R.id.bt_play);
        Button bt_pause=findViewById(R.id.bt_pause);
        Button bt_replay=findViewById(R.id.bt_replay);
        bt_play.setOnClickListener(this);
        bt_pause.setOnClickListener(this);
        bt_replay.setOnClickListener(this);

        if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!=PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
        }else{
            initMediaPlayer();
        }

    }


    public void initMediaPlayer(){
        try {
            //获取音频文件路径
            File file=new File(Environment.getExternalStorageDirectory(),"music.mp3");
            //设置要播放的音频文件的位置
            mediaPlayer.setDataSource(file.getPath());
            //进入播放前的准备状态
            mediaPlayer.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                if(grantResults.length>0 &&grantResults[0]== PackageManager.PERMISSION_GRANTED){
                    initMediaPlayer();
                }else {
                    Toast.makeText(this,"拒绝权限将无法使用该功能！",Toast.LENGTH_SHORT).show();
                }
                break;
            default:
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.bt_play:
                if(!mediaPlayer.isPlaying()){
                    mediaPlayer.start();
                }
                break;
            case R.id.bt_pause:
                if(mediaPlayer.isPlaying()){
                    mediaPlayer.pause();
                }
                break;
            case R.id.bt_replay:
                if(mediaPlayer.isPlaying()){
                    mediaPlayer.reset();
                    initMediaPlayer();
                }
                break;
            default:
                break;
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(mediaPlayer!=null){
            mediaPlayer.stop();
            mediaPlayer.release();
        }
    }
}

播放视频

主要就是利用VideoView类来实现

package cn.ywrby.videoviewtest;

import android.Manifest;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.widget.VideoView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import java.io.File;
import java.io.IOException;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private VideoView videoView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        videoView=findViewById(R.id.vv_video);
        Button bt_play=findViewById(R.id.bt_play);
        Button bt_pause=findViewById(R.id.bt_pause);
        Button bt_replay=findViewById(R.id.bt_replay);
        bt_play.setOnClickListener(this);
        bt_pause.setOnClickListener(this);
        bt_replay.setOnClickListener(this);

        if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
        }else{
            initVideoPath();
        }

    }


    public void initVideoPath(){
        File file=new File(Environment.getExternalStorageDirectory(),"movie.mp4");
        videoView.setVideoPath(file.getPath());
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                if(grantResults.length>0 &&grantResults[0]== PackageManager.PERMISSION_GRANTED){
                    initVideoPath();
                }else {
                    Toast.makeText(this,"拒绝权限将无法使用该功能！",Toast.LENGTH_SHORT).show();
                    finish();
                }
                break;
            default:
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.bt_play:
                if(!videoView.isPlaying()){
                    videoView.start();
                }
                break;
            case R.id.bt_pause:
                if(videoView.isPlaying()){
                    videoView.pause();
                }
                break;
            case R.id.bt_replay:
                if(videoView.isPlaying()){
                    videoView.resume();
                }
                break;
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(videoView!=null){
            videoView.suspend();
        }
    }
}