Android 的 READ_EXTERNAL_STORAGE 权限 [英] READ_EXTERNAL_STORAGE permission for Android
问题描述
我正在尝试访问用户设备上的媒体文件(音乐)来播放它们；一个简单的hello world"音乐播放器应用.
I'm trying to access media files (music) on the users device to play them; an easy "hello world"-music player app.
我遵循了一些教程，它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:
I've followed some tutorials and they basically give the same code. But it won't work; it keeps crashing and telling me:
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:
Now, this is my manifest file:
<?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:
This is my Java-method:
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());
}
}
我试过了:
要将其放在清单文件中的不同位置:
To put this at different places in the manifest file:
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
在读取外部存储权限中添加 android:maxSdkVersion:
To add android:maxSdkVersion at Read external storage premission:
<uses-permission
android:name="android.permission.READ_EXTERNAL_STORAGE"
android:maxSdkVersion="21" />
将其放在清单/应用程序/活动标签中:
To put this in the manifest / application / activity-tag:
android:exported="true"
在javamethod中将grantUriPremission放在uri和cursro之间:
To put grantUriPremission between uri and cursro in the javamethod:
grantUriPermission(null, uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
要使用它，它不会崩溃，但光标变为空:
To use this, it won't crash, but the cursor becomes null:
uri = MediaStore.Audio.Media.getContentUri("EXTERNAL_CONTENT_URI");
要使用内部内容 uri，这会按预期工作，但它只提供操作系统声音"，例如快门声音、低电量声音、按钮点击等:
To use INTERNAL content uri, this works as expected, but it only gives "OS-sounds" such as shutter-sound, low-battery-sound, button-click and such:
uri = MediaStore.Audio.Media.INTERNAL_CONTENT_URI;
请帮忙，我知道这应该不是一个很难的问题，但我觉得我是个初学者！
Pleas help, this should not be a hard problem i know, but i feel like such a beginner!
我已阅读并尝试过(或认为它们不适用于我的问题):
I have read and tried (or considered them to be not applicable for my problem):
- Android READ_EXTERNAL_STORAGE 权限无效
- 仅对较旧的 android 版本需要权限: maxSdkVersion 不起作用?
- 从媒体存储的 URI 中获取文件名和路径
- 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
推荐答案
对于您的问题，您有两种解决方案.最快的方法是将 targetApi 降低到 22(build.gradle 文件).二是使用新奇的请求权限模型:
You have two solutions for your problem. The quick one is to lower targetApi to 22 (build.gradle file). Second is to use new and wonderful ask-for-permission model:
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;
}
此处找到的 Sniplet:https://developer.android.com/training/permissions/请求.html
Sniplet found here: https://developer.android.com/training/permissions/requesting.html
解决方案 2:如果它不起作用试试这个:
Solutions 2: If it does not work try this:
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);
return;
}
然后在回调中
@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.
}
}
}
来自评论.谢谢
这篇关于Android 的 READ_EXTERNAL_STORAGE 权限的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
