Question

我正在开发一个需要读取和写入外部存储权限的应用程序。我已经在清单文件以及我的java活动文件中写入了所有权限但是我的应用程序一旦启动就仍然崩溃了抛出

的例外

permission denial:reading com.android.providers.media.MediaProvider

清单文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.abhi.scrolling_tab">

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

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".MainActivity"
        android:exported="true"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".Fragment_one"
        android:label="Fragment_one"
        android:theme="@style/AppTheme.NoActionBar" />
    <activity
        android:name=".Fragment_two"
        android:label="@string/title_activity_fragment_two"
        android:theme="@style/AppTheme.NoActionBar" />
    <activity
        android:name=".Fragment_three"
        android:label="@string/title_activity_fragment_three"
        android:theme="@style/AppTheme.NoActionBar"></activity>
</application>

Java文件

public class Fragment_two extends Fragment {
private RecyclerView recyclerView2;
private List<Model1> modelList;
private myAdapter2 adapter;
private MenuItem menu;


public Fragment_two() {
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.activity_fragment_two, container, false);
    ;
    recyclerView2 = (RecyclerView) view.findViewById(R.id.recycle2);
    int No_of_coloumns = 3;
    recyclerView2.setLayoutManager(new GridLayoutManager(getContext(), No_of_coloumns));
    modelList = getAllaudiofromdevice();
    adapter = new myAdapter2(modelList, (ViewGroup) view);
    recyclerView2.setAdapter(adapter);
    return view;
}

public List<Model1> getAllaudiofromdevice() {
    List<Model1> files = new ArrayList<>();
    try {
        ContentResolver contentResolver = getContext().getContentResolver();
        String selection = MediaStore.Audio.Media.IS_MUSIC;
        Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        String[] projection = {MediaStore.Audio.AudioColumns.DATA, MediaStore.Audio.AudioColumns.ALBUM, MediaStore.Audio.AudioColumns.ARTIST};
        Cursor c = contentResolver.query(uri, null, selection, null, null);
        if (c != null) {
            while (c.moveToNext()) {
                Model1 model1 = new Model1();
                String path = c.getString(0);
                String album = c.getString(1);
                String artist = c.getString(2);
                String name = path.substring(path.lastIndexOf('/') + 1);
                model1.setName(name);
                model1.setArtist(artist);
                model1.setAlbum(album);
                model1.setPath(path);
                files.add(model1);
            }
            c.close();
        }
    } catch (Exception e) {
        throw e;
    }
    check();
    return files;
}

public void check() {
    if (Build.VERSION.SDK_INT >= 23) {
        if (ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 123);
            return;
        }
    } else {
        getAllaudiofromdevice();
    }
}

@Override
public void onRequestPermissionsResult(int requestcode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    switch (requestcode) {
        case 123:
            if (grantResults[0] != PackageManager.PERMISSION_GRANTED) {
                getAllaudiofromdevice();
            } else {
                Toast.makeText(getContext(), "you have to set permissions", Toast.LENGTH_SHORT).show();
                check();
            }
        default:
            super.onRequestPermissionsResult(requestcode, permissions, grantResults);
    }

}

}

请帮我摆脱这个。谢谢你的期待。

Answer 1

仅在授予权限时才能工作。您的代码包含逻辑错误：

if (grantResults[0] != PackageManager.PERMISSION_GRANTED) { // Mistake here.
    getAllaudiofromdevice();
} //...

同样在API 23上，您的代码将在未被授予时请求权限，但在已经授予时将不执行任何操作（*）。它应该是这样的：

public void check() {
    if (Build.VERSION.SDK_INT >= 23 && ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        // Request permissions if they're not granted on API 23.
        requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 123);
    } else {
        // Do work on API <23 and when permissions were granted on API 23+.
        getAllaudiofromdevice();
    }
}

（*）根据您调用代码的方式，这实在令人困惑。

App崩溃抛出权限拒绝的例外：阅读com.android.providers.media.MediaProvider

1 个答案: