Android的READ_EXTERNAL_STORAGE权限

我试图访问用户设备上的媒体文件（音乐）来播放它们; 一个简单的“你好世界” – 音乐播放器的应用程序。

我跟着一些教程，他们基本上给出了相同的代码。 但它不会工作; 它不断崩溃，并告诉我： 

error..... Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=27696, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission() ....

现在，这是我的清单文件： 

 <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="slimsimapps.troff" > <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL"/> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>

这是我的Java方法： 

 public void initialize() { ContentResolver contentResolver = getContentResolver(); Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; Cursor cursor = contentResolver.query(uri, null, null, null, null); if (cursor == null) { // query failed, handle error. } else if (!cursor.moveToFirst()) { // no media on the device } else { do { addSongToXML(cursor); } while (cursor.moveToNext()); } }

我努力了：

把它放在清单文件的不同位置： 

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE”/>

在读取外部存储器时，添加android：maxSdkVersion： 

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="21" />

把这个放在manifest / application / activity-tag中： 

 android:exported=“true”

在uri和cursro之间放javaUriPremission java方法： 

 grantUriPermission(null, uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);

要使用它，它不会崩溃，但光标变为空： 

 uri = MediaStore.Audio.Media.getContentUri("EXTERNAL_CONTENT_URI”);

要使用INTERNAL内容uri，这可以按预期的方式工作，但它只会给出“OS声音”，例如快门声，低电量声，button点击等： 

 uri = MediaStore.Audio.Media.INTERNAL_CONTENT_URI;

请帮助，这不应该是我知道的一个难题，但我觉得这样的初学者！

我已阅读并尝试过（或认为它们不适用于我的问题）：

  • Android READ_EXTERNAL_STORAGE权限不起作用
  • 仅需要旧版android版本的权限：maxSdkVersion不起作用？
  • 从mediastore的URI获取文件名和path
  • 尝试从MediaStore读取时出现Android KitKat securityException
  • Android：java.lang.SecurityException：权限拒绝：启动意图

堆栈跟踪： 

 09-08 06:59:36.619 2009-2009/slimsimapps.troff D/AndroidRuntime﹕ Shutting down VM --------- beginning of crash 09-08 06:59:36.619 2009-2009/slimsimapps.troff E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: slimsimapps.troff, PID: 2009 java.lang.IllegalStateException: Could not execute method for android:onClick at android.view.View$DeclaredOnClickListener.onClick(View.java:4452) at android.view.View.performClick(View.java:5198) at android.view.View$PerformClick.run(View.java:21147) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at android.view.View$DeclaredOnClickListener.onClick(View.java:4447)            at android.view.View.performClick(View.java:5198)            at android.view.View$PerformClick.run(View.java:21147)            at android.os.Handler.handleCallback(Handler.java:739)            at android.os.Handler.dispatchMessage(Handler.java:95)            at android.os.Looper.loop(Looper.java:148)            at android.app.ActivityThread.main(ActivityThread.java:5417)            at java.lang.reflect.Method.invoke(Native Method)            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=2009, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission() at android.os.Parcel.readException(Parcel.java:1599) at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:183) at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:135) at android.content.ContentProviderProxy.query(ContentProviderNative.java:421) at android.content.ContentResolver.query(ContentResolver.java:491) at android.content.ContentResolver.query(ContentResolver.java:434) at slimsimapps.troff.MainActivity.initialize(MainActivity.java:106) at slimsimapps.troff.MainActivity.InitializeExternal(MainActivity.java:80)            at java.lang.reflect.Method.invoke(Native Method)            at android.view.View$DeclaredOnClickListener.onClick(View.java:4447)            at android.view.View.performClick(View.java:5198)            at android.view.View$PerformClick.run(View.java:21147)            at android.os.Handler.handleCallback(Handler.java:739)            at android.os.Handler.dispatchMessage(Handler.java:95)            at android.os.Looper.loop(Looper.java:148)            at android.app.ActivityThread.main(ActivityThread.java:5417)            at java.lang.reflect.Method.invoke(Native Method)            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) --------- beginning of system

你有两个解决你的问题。 最快的是将targetApi降低到22（build.gradle文件）。 其次是使用新的和精彩的请求许可模式： 

 if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { // Should we show an explanation? if (shouldShowRequestPermissionRationale( Manifest.permission.READ_EXTERNAL_STORAGE)) { // Explain to the user why we need to read the contacts } requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE); // MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE is an // app-defined int constant that should be quite unique return; }

Sniplet在这里find： https ： //developer.android.com/training/permissions/requesting.html

您在运行时要求获得许可： 

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_PERMISSION); dialog.dismiss(); return; }

而在下面的callback中，您可以访问存储没有问题。 

 @Override public void onRequestPermissionsResult(final int requestCode, @NonNull final String[] permissions, @NonNull final int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); if (requestCode == REQUEST_PERMISSION) { if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { // Permission granted. } else { // User refused to grant permission. } } }

你的问题解决了吗？ 你的目标SDK是什么？ 尝试添加android;maxSDKVersion="21"到<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

我也有一个类似的错误日志，这就是我所做的 –

  1. 在onCreate方法中，我们请求一个对话框来检查权限 

     ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},1);

  2. 检查结果的方法 

     @Override public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { switch (requestCode) { case 1: { // If request is cancelled, the result arrays are empty. if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { // permission granted and now can proceed mymethod(); //a sample method called } else { // permission denied, boo! Disable the // functionality that depends on this permission. Toast.makeText(MainActivity.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show(); } return; } // add other cases for more permissions } }

请求运行时权限的官方文档

第1步：在android manifest.xml中添加权限 

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Step2：onCreate（）方法 

 int permissionCheck = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE); if (permissionCheck != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_MEDIA); } else { readDataExternal(); }

第三步：重写onRequestPermissionsResult方法获取callback 

  @Override public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { switch (requestCode) { case MY_PERMISSIONS_REQUEST_READ_MEDIA: if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) { readDataExternal(); } break; default: break; } }

注意：readDataExternal（）是从外部存储获取数据的方法。

谢谢。

http://developer.android.com/reference/android/provider/MediaStore.Audio.AudioColumns.html

尝试改变行contentResolver.query 

 //change it to the columns you need String[] columns = new String[]{MediaStore.Audio.AudioColumns.DATA}; Cursor cursor = contentResolver.query(uri, columns, null, null, null);

public static final String MEDIA_CONTENT_CONTROL

由于媒体消费的隐私，不能用于第三方应用程序

http://developer.android.com/reference/android/Manifest.permission.html#MEDIA_CONTENT_CONTROL

尝试先删除<uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL"/>然后再试一次？

请检查下面的代码，使用它你可以find所有的音乐文件从SD卡： 

 public class MainActivity extends Activity{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_animations); getAllSongsFromSDCARD(); } public void getAllSongsFromSDCARD() { String[] STAR = { "*" }; Cursor cursor; Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0"; cursor = managedQuery(allsongsuri, STAR, selection, null, null); if (cursor != null) { if (cursor.moveToFirst()) { do { String song_name = cursor .getString(cursor .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME)); int song_id = cursor.getInt(cursor .getColumnIndex(MediaStore.Audio.Media._ID)); String fullpath = cursor.getString(cursor .getColumnIndex(MediaStore.Audio.Media.DATA)); String album_name = cursor.getString(cursor .getColumnIndex(MediaStore.Audio.Media.ALBUM)); int album_id = cursor.getInt(cursor .getColumnIndex(MediaStore.Audio.Media.ALBUM_ID)); String artist_name = cursor.getString(cursor .getColumnIndex(MediaStore.Audio.Media.ARTIST)); int artist_id = cursor.getInt(cursor .getColumnIndex(MediaStore.Audio.Media.ARTIST_ID)); System.out.println("sonng name"+fullpath); } while (cursor.moveToNext()); } cursor.close(); } } }

我还在AndroidManifest.xml文件中添加了以下行： 

 <uses-sdk android:minSdkVersion="16" android:targetSdkVersion="17" /> <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

除了所有的答案。 您也可以指定minsdk以应用此注释 

 @TargetApi(_apiLevel_)

我用这个来接受这个请求，即使我的minsdk是18，它所做的只是当设备的目标是“_apilevel_”和upper时才运行。 这是我的方法： 

  @TargetApi(23) void solicitarPermisos(){ if (ContextCompat.checkSelfPermission(this,permiso) != PackageManager.PERMISSION_GRANTED) { // Should we show an explanation? if (shouldShowRequestPermissionRationale( Manifest.permission.READ_EXTERNAL_STORAGE)) { // Explain to the user why we need to read the contacts } requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1); // MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE is an // app-defined int constant that should be quite unique return; } }

只需进入“设置”，在“设备”下select“应用程序”，然后滚动到您的MY_APPLICATION并授予“存储”权限。

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