2013-07-10 96 views
1

我和我的朋友正在創建一個android應用程序。我們幾乎做到了這一點...應用程序將在第一次運行時同時播放兩個聲音,但在第二次運行時它會拋出一些錯誤並達到ANR狀態。如何解決這個問題?檢查下面的logcat和代碼。如何使用MediaPlayer同時播放兩個或多個音頻剪輯(android)

代碼

import java.io.IOException; 

import android.app.Activity; 
import android.media.MediaPlayer; 
import android.media.MediaPlayer.OnCompletionListener; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 

public class MainActivity extends Activity implements OnClickListener,Runnable { 

    boolean mBound = false; 
    Button btn1,btn2; 
    Button btn3; 
    Button btn4; 
    MediaPlayer yourStereo; 

    MediaPlayer myStereo; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     btn1=(Button)findViewById(R.id.a_button); 
     btn2=(Button)findViewById(R.id.b_button); 
     btn3=(Button)findViewById(R.id.c_button); 
     btn4=(Button)findViewById(R.id.d_button); 


     btn1.setOnClickListener(this); 
     myStereo = MediaPlayer.create(this, R.raw.brb); 
     btn3.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       btn3.setVisibility(Button.GONE); 
       btn4.setVisibility(Button.VISIBLE); 
       // TODO Auto-generated method stub 



         try { 
          myStereo.prepare(); 
         } catch (IllegalStateException e) { 
          // TODO Auto-generated catch block 
          e.printStackTrace(); 
         } catch (IOException e) { 
          // TODO Auto-generated catch block 
          e.printStackTrace(); 
         } 
         myStereo.setLooping(true); 
         myStereo.start(); 
         myStereo.setOnCompletionListener(new OnCompletionListener() { 

          @Override 
          public void onCompletion(MediaPlayer mp) { 
           // TODO Auto-generated method stub 
           myStereo.setLooping(true); 
           myStereo.release(); 
           try { 
            myStereo.prepare(); 
           } catch (IllegalStateException e) { 
            // TODO Auto-generated catch block 
            e.printStackTrace(); 
           } catch (IOException e) { 
            // TODO Auto-generated catch block 
            e.printStackTrace(); 
           } 
           myStereo.start(); 
          } 
         }); 
         // pause music here 

         btn4.setOnClickListener(new View.OnClickListener() { 

          @Override 
          public void onClick(View v) { 
           // TODO Auto-generated method stub 
           myStereo.stop(); 
           btn4.setVisibility(Button.GONE); 
           btn3.setVisibility(Button.VISIBLE); 

          } 
         }); 
      } 
     }); 



    } 

    @Override 
    public void onClick(View arg0) { 
      // play music here 
      btn1.setVisibility(Button.GONE); 
      btn2.setVisibility(Button.VISIBLE); 
      // TODO Auto-generated method stub 
      yourStereo = MediaPlayer.create(this, R.raw.pl); 
      yourStereo.setLooping(true); 
      try { 
       yourStereo.prepare(); 
      } catch (IllegalStateException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
      } catch (IOException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
      } 
        yourStereo.start(); 
        yourStereo.setOnCompletionListener(new OnCompletionListener() { 

         @Override 
         public void onCompletion(MediaPlayer mp) { 
          // TODO Auto-generated method stub 
          yourStereo.setLooping(true); 
          yourStereo.release(); 
          try { 
           yourStereo.prepare(); 
          } catch (IllegalStateException e) { 
           // TODO Auto-generated catch block 
           e.printStackTrace(); 
          } catch (IOException e) { 
           // TODO Auto-generated catch block 
           e.printStackTrace(); 
          } 
          yourStereo.start(); 
         } 
        }); 
      // pause music here 

      btn2.setOnClickListener(new View.OnClickListener() { 

       @Override 
       public void onClick(View v) { 
        // TODO Auto-generated method stub 
        yourStereo.stop(); 
        btn2.setVisibility(Button.GONE); 
        btn1.setVisibility(Button.VISIBLE); 

       } 
      }); 
    } 


    @Override 
    public void run() { 
     // TODO Auto-generated method stub 

    } 

} 

logcat的

07-08 11:44:17.245: W/System.err(2659): java.lang.IllegalStateException 
07-08 11:44:17.261: W/System.err(2659):  at android.media.MediaPlayer.prepare(Native Method) 
07-08 11:44:17.261: W/System.err(2659):  at com.example.sleepsimulator.MainActivity$1.onClick(MainActivity.java:49) 
07-08 11:44:17.269: W/System.err(2659):  at android.view.View.performClick(View.java:2485) 
07-08 11:44:17.269: W/System.err(2659):  at android.view.View$PerformClick.run(View.java:9080) 
07-08 11:44:17.269: W/System.err(2659):  at android.os.Handler.handleCallback(Handler.java:587) 
07-08 11:44:17.269: W/System.err(2659):  at android.os.Handler.dispatchMessage(Handler.java:92) 
07-08 11:44:17.269: W/System.err(2659):  at android.os.Looper.loop(Looper.java:130) 
07-08 11:44:17.269: W/System.err(2659):  at android.app.ActivityThread.main(ActivityThread.java:3687) 
07-08 11:44:17.269: W/System.err(2659):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-08 11:44:17.269: W/System.err(2659):  at java.lang.reflect.Method.invoke(Method.java:507) 
07-08 11:44:17.269: W/System.err(2659):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
07-08 11:44:17.269: W/System.err(2659):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
07-08 11:44:17.269: W/System.err(2659):  at dalvik.system.NativeStart.main(Native Method) 
07-08 11:44:20.534: W/KeyCharacterMap(2659): Can't open keycharmap file 
07-08 11:44:20.534: W/KeyCharacterMap(2659): Error loading keycharmap file 
07-08 11:44:20.534: W/KeyCharacterMap(2659): Using default keymap 
07-08 11:44:26.636: W/System.err(2659): java.io.IOException: Prepare failed.: status=0xFFFFFF8E 
07-08 11:44:26.636: W/System.err(2659):  at android.media.MediaPlayer.prepare(Native Method) 
07-08 11:44:26.636: W/System.err(2659):  at com.example.sleepsimulator.MainActivity$1.onClick(MainActivity.java:49) 
07-08 11:44:26.636: W/System.err(2659):  at android.view.View.performClick(View.java:2485) 
07-08 11:44:26.636: W/System.err(2659):  at android.view.View$PerformClick.run(View.java:9080) 
07-08 11:44:26.636: W/System.err(2659):  at android.os.Handler.handleCallback(Handler.java:587) 
07-08 11:44:26.636: W/System.err(2659):  at android.os.Handler.dispatchMessage(Handler.java:92) 
07-08 11:44:26.636: W/System.err(2659):  at android.os.Looper.loop(Looper.java:130) 
07-08 11:44:26.636: W/System.err(2659):  at android.app.ActivityThread.main(ActivityThread.java:3687) 
07-08 11:44:26.636: W/System.err(2659):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-08 11:44:26.636: W/System.err(2659):  at java.lang.reflect.Method.invoke(Method.java:507) 
07-08 11:44:26.636: W/System.err(2659):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
07-08 11:44:26.636: W/System.err(2659):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
07-08 11:44:26.636: W/System.err(2659):  at dalvik.system.NativeStart.main(Native Method) 
07-08 11:44:26.636: E/MediaPlayer(2659): start called in state 64 
07-08 11:44:26.636: E/MediaPlayer(2659): error (-38, 0) 
07-08 11:44:34.643: E/MediaPlayer(2659): stop called in state 0 
07-08 11:44:34.643: E/MediaPlayer(2659): error (-38, 0) 
07-08 11:44:34.643: E/MediaPlayer(2659): Error (-38,0) 
07-08 11:44:34.651: W/System.err(2659): java.lang.IllegalStateException 
07-08 11:44:34.675: W/System.err(2659):  at android.media.MediaPlayer.prepare(Native Method) 
07-08 11:44:34.675: W/System.err(2659):  at com.example.sleepsimulator.MainActivity$1$1.onCompletion(MainActivity.java:67) 
07-08 11:44:34.675: W/System.err(2659):  at android.media.MediaPlayer$EventHandler.handleMessage(MediaPlayer.java:1475) 
07-08 11:44:34.675: W/System.err(2659):  at android.os.Handler.dispatchMessage(Handler.java:99) 
07-08 11:44:34.675: W/System.err(2659):  at android.os.Looper.loop(Looper.java:130) 
07-08 11:44:34.675: W/System.err(2659):  at android.app.ActivityThread.main(ActivityThread.java:3687) 
07-08 11:44:34.675: W/System.err(2659):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-08 11:44:34.675: W/System.err(2659):  at java.lang.reflect.Method.invoke(Method.java:507) 
07-08 11:44:34.675: W/System.err(2659):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
07-08 11:44:34.675: W/System.err(2659):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
07-08 11:44:34.675: W/System.err(2659):  at dalvik.system.NativeStart.main(Native Method) 
07-08 11:44:34.675: W/dalvikvm(2659): threadid=1: thread exiting with uncaught exception (group=0x40018578) 
07-08 11:44:34.683: E/AndroidRuntime(2659): FATAL EXCEPTION: main 
07-08 11:44:34.683: E/AndroidRuntime(2659): java.lang.IllegalStateException 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at android.media.MediaPlayer._start(Native Method) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at android.media.MediaPlayer.start(MediaPlayer.java:950) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at com.example.sleepsimulator.MainActivity$1$1.onCompletion(MainActivity.java:75) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at android.media.MediaPlayer$EventHandler.handleMessage(MediaPlayer.java:1475) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at android.os.Handler.dispatchMessage(Handler.java:99) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at android.os.Looper.loop(Looper.java:130) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at android.app.ActivityThread.main(ActivityThread.java:3687) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at java.lang.reflect.Method.invoke(Method.java:507) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
07-08 11:44:34.683: E/AndroidRuntime(2659):  at dalvik.system.NativeStart.main(Native Method) 

回答

2

你所得到的錯誤是由於您的onCompletionListener

.release()釋放所有資源調用.release()其次.prepare()如果您不想再使用MediaPlayer,只能在您的應用退出時纔會調用該功能。

http://developer.android.com/reference/android/media/MediaPlayer.html#release()

因此.release()後您到.prepare()調用失敗,因爲它不知道哪些準備。

如果您只是再次播放同一個文件,您可以再次撥打.start() onCompletion。我相信它會回到起點。無需再次發佈和準備。

此外,如果您使用的是.create(),則根本不需要撥打.prepare(),因爲它已經處於準備狀態。

http://developer.android.com/reference/android/media/MediaPlayer.html#create(android.content.Context, android.net.Uri, android.view.SurfaceHolder)

+1

感謝您的支持:) – Niko

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