Java 如何在以下程序中实现onRequestPermissionsResult

我正在制作一个音乐播放器应用程序，并在其中创建了一个播放列表。对于棉花糖设备（API 6.0.0），我需要获得读取外部存储的权限。因此，我创建了一个类Permission.java，以便在需要权限时请求权限（所有有关检查权限和请求权限的方法都在其中实现，在这个应用程序中，我使用的是Permission.java实例）。但是我不确定在哪里应该实现方法onRequestPermissionsResult（）？ 在这些上传的文件中，我在Permission.java中实现了onRequestPermissionsResult（）

请帮忙

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);
}
    }

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>

---

使用permissions类不是一种很好的方法

在需要权限的活动中，只需呼叫：

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

---

同样在同一个活动中，在

onRequestPermissionsResult

方法中相应地处理请求

类权限扩展ActivityCompat

+构造函数：

权限（活动活动、上下文上下文、字符串Per、视图视图、最终整数请求\u代码）

=请学习一些Android的基础知识（权限是一个活动类-为什么要将活动传递给它？；活动是上下文-为什么也要传递它？；活动构造函数应该是无参数的，决不能对扩展活动的类使用新运算符）阅读文档：它解释了一切。删除

Permission.java

。您不能创建

ActivityCompat

的随机子类并期望它工作。将权限检查逻辑移动到

MainActivity

。或者，使用其中任何一个。非常感谢Selvin、Kuffs、Commonware。我正在将权限方法移动到MainActivity非常感谢，Kuffs。我是Android新手，是的，现在我将从MainActivity而不是任何其他类调用该方法：）

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

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