安卓开发之Intent系统调用系统相机Camera（中软杯项目）

最新推荐文章于 2022-04-17 10:26:38 发布

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最新推荐文章于 2022-04-17 10:26:38 发布 · 1.2k 阅读

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本文介绍了解决Android应用中遇到的FileUriExposedException异常的方法，探讨了Android 7.0及以上版本中动态权限申请的重要性，并提供了解决方案来避免权限问题导致的程序崩溃。此外，还详细介绍了如何正确处理拍照后的图片显示问题。

文章目录

package com.example.software_china;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import java.io.File;

public class MainActivity extends AppCompatActivity {
   
   

            private  Button bt_camera;

        	private  Button bt_show_imag;

            private  ImageView iv_image;

            private  File file;



            @Override
    protected void onCreate(Bundle savedInstanceState) {
   
   

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

         bt_camera=(Button) findViewById(R.id.bt_camera);

         iv_image =(ImageView) findViewById(R.id.iv_image);

        bt_show_imag =(Button) findViewById(R.id.bt_show_imag);

        bt_camera.setOnClickListener(new View.OnClickListener() {
   
   
            @Override
            public void onClick(View v) {
   
   

                file=new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");

        Intent intent=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));

        startActivityForResult(intent,100);
            }
        });

        bt_show_imag.setOnClickListener(new View.OnClickListener() {
   
   
            @Override
            public void onClick(View v) {
   
   
            Intent intent=new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(Uri.fromFile(file),"image/*");
            startActivity(intent);
            }
        }


        );
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
   
   
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode==100){
   
   

            iv_image.setImageURI(Uri.fromFile(file));

        }
    }
}

写完之后，一点就闪退，调试后，原因如下：

出现了FileUriExposedException

2021-05-09 15:50:12.100 1727-1727/com.example.software_china E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.software_china, PID: 1727
    android.os.FileUriExposedException: file:///storage/emulated/0/1620546589434.jpg exposed beyond app through ClipData.Item.getUri()
        at android.os.StrictMode.onFileUriExposed(StrictMode.java:1978)
        at android.net.Uri.checkFileUriExposed(Uri.java:2371)
        at android.content.ClipData.prepareToLeaveProcess(ClipData.java:963)
        at android.content.Intent.prepareToLeaveProcess(Intent.java:10331)
        at android.content.Intent.prepareToLeaveProcess(Intent.java:10316)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1667)
        at android.app.Activity.startActivityForResult(Activity.java:4762)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:675)
        at android.app.Activity.startActivityForResult(Activity.java:4691)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:662)
        at com.example.software_china.MainActivity$1.onClick(MainActivity.java:48)
        at android.view.View.performClick(View.java:6724)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
        at android.view.View.performClickInternal(View.java:6682)
        at android.view.View.access$3400(View.java:797)
        at android.view.View$PerformClick.run(View.java:26479)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:242)
        at android.app.ActivityThread.main(ActivityThread.java:7227)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:499)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:962)

总之呢，就是FileUriExposedException报错

原因：

对于面向 Android 7.0 的应用，Android 框架执行的 StrictMode API 政策禁止在应用外部公开 file:// URI ，如果一项包含文件 URI 的 intent 离开应用，则应用出现故障，并出现 FileUriExposedException 异常（需要把它封装一下）

然后改成

出现了动态权限问题

package com.example.software_china;

import android.Manifest;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import java.io.File;

public class MainActivity extends AppCompatActivity {
   
   

            private  Button bt_camera;

            private  Button bt_show_imag;

            private  ImageView iv_image;

            int writeflag = 0;//判断储存权限是否获取



    public void openCamera() {
   
   

        Intent intent=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        intent.putExtra(MediaStore.EXTRA_OUTPUT, getImageUri());

        startActivityForResult(intent,100);
    }

    public Uri getImageUri() {
   
   
        Uri imageUri;
        File  file=new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");
        if (