如何在以下程序

时间：2016-02-04 15:57:55

标签： java android permissions invoke

我正在制作音乐播放器应用并在其中创建了一个播放列表。对于marshmallow设备（API 6.0.0），我需要获得READ_EXTERNAL_STORAGE权限。所以我创建了一个类Permission.java，以便在需要时请求权限（关于检查权限和请求它的所有方法都在其中实现，在此应用程序中我使用的是Permission.java实例）。但我不确定方法 onRequestPermissionsResult（）我应该在哪里实现它。如果在权限类本身那么如何在MainActivity.java中如何？ 在这些上传的文件中，我在Permission.java中实现了 onRequestPermissionsResult（）

请帮助！

MainActivity.java 

    package com.abhi.music.musicplayer1;

    import android.Manifest;
    import android.content.ContentResolver;
    import android.content.ContentUris;
    import android.content.pm.PackageManager;
    import android.database.Cursor;
    import android.media.AudioManager;
    import android.media.MediaPlayer;
    import android.net.Uri;
    import android.os.Bundle;
    import android.os.Environment;
    import android.provider.MediaStore;
    import android.support.design.widget.CoordinatorLayout;
    import android.support.design.widget.FloatingActionButton;
    import android.support.design.widget.Snackbar;
    import android.support.v4.content.ContextCompat;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;
    import android.util.Log;
    import android.view.View;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.widget.ArrayAdapter;
    import android.widget.ListView;
    import android.widget.TextView;
    import android.widget.Toast;

    import java.io.File;
    import java.io.IOException;
    import java.util.ArrayList;

    public class MainActivity extends AppCompatActivity {

public String TAG="permission_log";
private static final File EXTERNAL_LOCATION= Environment.getExternalStorageDirectory();
ListView PlaylistView;
TextView tV;
ArrayList<String> songNamesList= new ArrayList<String>();
String[] songNamesInStringArray;
private static final int REQUEST_CODE= 1;

public long sampleID;

Permission permission;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    tV= (TextView) findViewById(R.id.textView);

    permission= new Permission(this,getApplicationContext(),Manifest.permission.READ_EXTERNAL_STORAGE,tV,REQUEST_CODE);
    permission.permission_allowed();
    //PlaylistView= (ListView) findViewById(R.id.PlaylistView);




    //findMediaFromSD();
    //findMediaFromInternal();
    //songNamesInStringArray= new String[songNamesList.size()];
    //songNamesInStringArray= songNamesList.toArray(songNamesInStringArray);


    //ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getApplicationContext(),R.layout.listview_layout,songNamesInStringArray);
    ///PlaylistView.setAdapter(arrayAdapter);

    //Toast.makeText(getApplicationContext(),songNamesInStringArray[1],Toast.LENGTH_LONG).show();
    //playMusic();


}



public void findMediaFromSD()
{
    ContentResolver contentResolver = getContentResolver();
    Uri uri = android.provider.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 {
        int titleColumn = cursor.getColumnIndex(android.provider.MediaStore.Audio.Media.TITLE);
        int idColumn = cursor.getColumnIndex(android.provider.MediaStore.Audio.Media._ID);
        do {
            long thisId = cursor.getLong(idColumn);
            sampleID=thisId;
            String thisTitle = cursor.getString(titleColumn);
            // ...process entry...
           // Toast(thisTitle);
            Log.d("Add hua?", "beforre adding in songNameslist");
            songNamesList.add(thisTitle);
            Log.d("Add hua?", "after adding in songNameslist");
        } while (cursor.moveToNext());
    }
}

public void findMediaFromInternal()
{
    ContentResolver contentResolver = getContentResolver();
    Uri uri = android.provider.MediaStore.Audio.Media.INTERNAL_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 {
        int titleColumn = cursor.getColumnIndex(android.provider.MediaStore.Audio.Media.TITLE);
        int idColumn = cursor.getColumnIndex(android.provider.MediaStore.Audio.Media._ID);
        do {
            long thisId = cursor.getLong(idColumn);
            String thisTitle = cursor.getString(titleColumn);
            // ...process entry...
            // Toast(thisTitle);
            Log.d("Add hua?", "before adding in songNameslist");
            songNamesList.add(thisTitle);
            Log.d("Add hua?", "after adding in songNameslist");
        } while (cursor.moveToNext());
    }
}


public  void playMusic()
{
    Uri contentUri= ContentUris.withAppendedId(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,sampleID);
    MediaPlayer mp= new MediaPlayer();
    mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
    try {
        mp.setDataSource(getApplicationContext(), contentUri);
    } catch (IOException e) {
        e.printStackTrace();
        Log.d("Media","Error");
    }

    mp.start();
    Toast("mp started");
    Toast.makeText(getApplicationContext(),"sample id is"+ sampleID,Toast.LENGTH_LONG);



}

public void Toast(String text)
{
    Toast.makeText(getApplicationContext(),text,Toast.LENGTH_SHORT).show();
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
    }

Permission.java 类是

package com.abhi.music.musicplayer1;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

/**
 * Created by abhi on 2/3/2016.
 */
public class Permission extends ActivityCompat{
    private String Per;         // Remember to put the per string as     menifest.permission.READ_EXTERNAL_SOURCE or any other READ_...
private Context context;
private View view;
private Activity activity;
private static final int PERMISSION_REQUEST_CODE = 1;
private static final int Request_code=1;


public String TAG="permission_log";

public Permission(Activity activity,Context context,String Per, View view, final int Request_code)
{
    this.activity=activity;
    this.Per=Per;
    this.context=context;
    this.view=view;
    //this.Request_code=Request_code;

}

public void permission_allowed(){
        checkPermission();
    Log.v(TAG, "check permission done");
        RequestPermission();
    Log.v(TAG, "request permission done");

}


public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    Log.v(TAG,"mil gayi hai");
    switch (requestCode) {
        case PERMISSION_REQUEST_CODE: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the
                // contacts-related task you need to do.
                Log.v(TAG,"mil gayi hai");


            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
                Log.v(TAG,"mil gayi hai");
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request
    }
}

private boolean checkPermission()
{
    int permissionCheck = ContextCompat.checkSelfPermission(context,
            Per);
    //Log.v(TAG, "true");
    if(permissionCheck==PackageManager.PERMISSION_GRANTED)
    {
       // Log.v(TAG,"true");
        return true;
    }
    else   {
        //Log.v(TAG,"true");

        return false;
    }
    }

private void RequestPermission() {
    Log.v(TAG,"in Request permission");
    if (!checkPermission()) {
        Log.v(TAG,"in Request permission, check permission false");
        if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Per)) {
            Toast.makeText(context, "second time aa raha hai", Toast.LENGTH_LONG).show();
            Log.v(TAG, "in Request permission, check permission false and not first time");
        }

        else
        {
            Log.v(TAG,"in Request permission, check permission false and not first time");
            ActivityCompat.requestPermissions(activity,
                    new String[]{Per},
                    Request_code);
            Toast.makeText(context, "First time aa raha hai", Toast.LENGTH_LONG).show();
        }
    }
    else {
        Log.v(TAG,"in Request permission, check permission false");
    }
}



}

Content_main.xml 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/activity_main" tools:context=".MainActivity">


<ListView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/PlaylistView"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:backgroundTint="#accef6"
    android:layout_above="@+id/textView" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Large Text"
    android:id="@+id/textView"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="68dp" />
</RelativeLayout>

错误我得到的是

02-04 10:02:51.246 12267-12288/com.abhi.music.musicplayer1 E/Surface: getSlotFromBufferLocked: unknown buffer: 0xeac09230
02-04 10:02:51.889 12267-12288/com.abhi.music.musicplayer1 E/Surface: getSlotFromBufferLocked: unknown buffer: 0xeac09310

1 个答案:

答案 0 :(得分：3)

使用权限类不是一种好办法。

在您需要权限的活动中，只需致电：

ActivityCompat.requestPermissions(this,
                new String[]{Per},
                Request_code);

并且在同一个Activity中，相应地处理onRequestPermissionsResult方法中的请求

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