我正在尝试访问用户设备上的媒体文件(音乐)以进行播放;一个简单的“ hello world”音乐播放器应用。
我遵循了一些教程,它们基本上给出了相同的代码。但这是行不通的。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:
要将其放在清单文件中的不同位置:
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE”/>
要在读取外部存储权限下添加android:maxSdkVersion:
<uses-permission
android:name="android.permission.READ_EXTERNAL_STORAGE"
android:maxSdkVersion="21" />
要将其放在清单/应用程序/活动标签中:
android:exported=“true”
将uri和cursro之间的grantUriPremission放在javamethod中:
grantUriPermission(null, uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
要使用它,它不会崩溃,但是光标变为空:
uri = MediaStore.Audio.Media.getContentUri("EXTERNAL_CONTENT_URI”);
要使用INTERNAL内容uri,它可以按预期工作,但是只能给出“ OS声音”,例如快门声,电池电量低,单击按钮等:
uri = MediaStore.Audio.Media.INTERNAL_CONTENT_URI;
请帮助,这不是我所知道的难题,但我感觉自己像是一个初学者!
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
- 只需要旧版android的权限:maxSdkVersion不起作用?
- 从Mediastore的URI获取文件名和路径
- 尝试从MediaStore读取时,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