如何在Android中播放媒體文件

Question

我收聽了我手機中的歌曲， 但我無法播放歌曲。請幫幫我。我使用setOnDataSource，但我無法得到它。在文檔中，它顯示使用setDataSource（）。請提出任何更正以使代碼非常完美 以下是代碼： package com.example.testmedia;

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

import android.media.MediaPlayer; 
import android.net.Uri; 
import android.os.Bundle; 
import android.provider.MediaStore; 
import android.app.Activity; 
import android.app.ListActivity; 
import android.content.ContentResolver; 
import android.content.ContentUris; 
import android.database.Cursor; 
import android.view.Menu; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.widget.Toast; 

public class Tracks_media extends Activity implements OnItemClickListener { 




MediaPlayer mediaplayer; 
String Displayname="",id=""; 
Cursor cursor; 
List<String> musiclist=new ArrayList<String>(); 
ListView tracklist; 
ArrayAdapter<String> itemusic; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_tracks_media); 
    tracklist=(ListView)findViewById(R.id.TrackList); 
    itemusic=new ArrayAdapter<String>(this,  
      android.R.layout.simple_list_item_1, musiclist); 
    mediaplayer=new MediaPlayer(); 
    tracklist.setAdapter(itemusic); 
    Loadmusic(); 
    tracklist.setOnItemClickListener(this); 
} 

//Retrive all songs 
private void Loadmusic() { 
    // TODO Auto-generated method stub 
    ContentResolver cr=getContentResolver(); 
    Uri uri=MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; 
    cursor=cr.query(uri, null, null, null, null); 
    if(cursor==null) 
    { 
     Toast.makeText(this, "No media Files present",   
      Toast.LENGTH_SHORT).show(); 



    } 
    while (cursor.moveToNext()) 
    { 


Displayname=cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE)); 

id=cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media._ID)); 
     itemusic.add(id+"\t"+Displayname+""); 
    } 


    cursor.close(); 

} 



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



@Override 
public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) { 
    // TODO Auto-generated method stub 
    mediaplayer.reset(); 
    try { 
     mediaplayer.setDataSource(musiclist.get(position)); 
     mediaplayer.prepare(); 
     mediaplayer.start(); 
    } catch (IllegalStateException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 

} 


} 

我嘗試了很多方法，但無法做到正確。 請告訴我如何播放retrived媒體。

Answer 1

最後我得到了解決。這裏是代碼

import java.util.ArrayList; 
import android.media.AudioManager; 
import android.media.MediaPlayer; 
import android.net.Uri; 
import android.os.Bundle; 
import android.provider.MediaStore; 
import android.app.Activity; 
import android.content.Context; 
import android.database.Cursor; 
import android.view.Menu; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 


public class Tracks extends Activity implements OnItemClickListener { 


    ListView lv; 
    ArrayList<String> songs; 
    ArrayAdapter<String> adapter; 
    AudioManager am; 
    MediaPlayer mp; 
    Cursor cursor; 
@Override 
protected void onCreate(Bundle savedInstanceState) 
{ 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_tracks); 
    lv=(ListView)findViewById(R.id.Tracks); 
    am=(AudioManager)getSystemService(Context.AUDIO_SERVICE); 
    loadMusic(); 
    adapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,songs); 
    lv.setAdapter(adapter); 
    lv.setOnItemClickListener(this); 
} 

    @SuppressWarnings("deprecation") 
    private void loadMusic() 
    { 
     Uri uri=android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; 
     String projection[]=  
    {android.provider.MediaStore.Audio.Media.DATA,android.provider.MediaStore.Audio.Media.TITLE}; 
     cursor=this.managedQuery(uri, projection, null, null, null); 
     songs=new ArrayList<String>(); 
     while (cursor.moveToNext()) { 

      String duration=android.provider.MediaStore.Audio.Media.DURATION; 
      songs.add(cursor.getString(1)+"\t"+duration); 
     } 

    } 

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

    @Override 
    public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) 
    { 

     cursor.moveToPosition(position); 
     //Toast.makeText(getBaseContext(), songs.get(position), Toast.LENGTH_SHORT).show(); 
     int id1=cursor.getColumnIndex(MediaStore.Audio.Media.DATA); 
     //Uri filename=ContentUris.withAppendedId(android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, id); 
     mp=new MediaPlayer(); 
     //mp.reset(); 
     try 
     { 
      mp.setAudioStreamType(AudioManager.STREAM_MUSIC); 
      mp.setDataSource(cursor.getString(id1)); 
      mp.prepare(); 
      mp.start(); 
     } 
     catch (Exception e) { 
      // TODO: handle exception 
      e.printStackTrace(); 
     } 

    } 

    @Override 
    protected void onDestroy() { 
     // TODO Auto-generated method stub 
     super.onDestroy(); 
     mp.release(); 
    } 

    @Override 
    protected void onPause() { 
     // TODO Auto-generated method stub 
     super.onPause(); 
    } 

    @Override 
    protected void onRestart() { 
     // TODO Auto-generated method stub 
     super.onRestart(); 
    } 

    @Override 
    protected void onResume() { 
     // TODO Auto-generated method stub 
     super.onResume(); 
    } 

} 

Answer 2

嘗試增加：

cursor=cr.query(uri, new String[] {"*"}, null, null, null); 

，並嘗試MediaPlayer創建新實例，而不是mediaPlayer.reset();

如果不工作，see this。

Answer 3

試試這個編輯代碼

public class bcd extends Activity implements OnItemClickListener { 




MediaPlayer mediaplayer; 
String Displayname="",id=""; 
Cursor cursor; 
List<String> musiclist=new ArrayList<String>(); 
ListView tracklist; 
ArrayAdapter<String> itemusic; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_tracks_media); 
tracklist=(ListView)findViewById(R.id.TrackList); 


mediaplayer=new MediaPlayer(); 

Loadmusic(); 
tracklist.setOnItemClickListener(this); 
} 

//Retrive all songs 
private void Loadmusic() { 
// TODO Auto-generated method stub 
ContentResolver cr=getContentResolver(); 
Uri uri=MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; 
cursor=cr.query(uri, null, null, null, null); 
if(cursor==null) 
{ 
    Toast.makeText(this, "No media Files present",   
     Toast.LENGTH_SHORT).show(); 



} 
while (cursor.moveToNext()) 
{ 


Displayname=cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE)); 

id=cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media._ID)); 
    musiclist.add(id+"\t"+Displayname+""); 
} 


cursor.close(); 
itemusic=new ArrayAdapter<String>(this,  
     android.R.layout.simple_list_item_1, musiclist); 
tracklist.setAdapter(itemusic); 
} 



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



@Override 
public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) { 
// TODO Auto-generated method stub 
mediaplayer.reset(); 
try { 
    mediaplayer.setDataSource(musiclist.get(position)); 
    mediaplayer.prepare(); 
    mediaplayer.start(); 
} catch (IllegalStateException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
} catch (IOException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
} 

}