Fehler beim Ausführen von Code auf Android-Spiel

Question

Ich mache ein Android-Spiel, das eine Nachricht anzeigen sollte, dass Sie einen bestimmten Punkt verloren haben. Aber sein Versagen aus irgendeinem Grund, dass ich möglicherweise nicht herausfinden kann. Auf checkLivesLeftValue() ruft onMethod() auf, wenn der Benutzer alle drei Leben verbraucht hat, die er erhalten hat. Aber dann, wenn ich einen Toast mache, scheitert die Anwendung, warum ???

Das ist mein Java-Code:

import java.util.ArrayList; 

import android.app.AlertDialog; 
import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.os.Handler; 
import android.os.Message; 
import android.view.MotionEvent; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.widget.TextView; 
import android.widget.Toast; 

public class ExampleView extends SurfaceView implements SurfaceHolder.Callback 
{ 
class ExampleThread extends Thread 
{ 
    private ArrayList<Parachuter> parachuters; 
    private Bitmap parachuter; 
    private Paint black; 

    private boolean running; 

    private SurfaceHolder mSurfaceHolder; 
    private Context mContext; 
    private Handler mHandler; 
    private GameScreenActivity mActivity; 

    private long frameRate; 
    private boolean loading; 
    public float x; 
    public float y; 
    public MediaPlayer mp1; 
    public int parachuterIndexToResetAndDelete; 
    public int canvasGetWidth; 
    public int livesLeftValue; 

    public ExampleThread(SurfaceHolder sHolder, Context context, Handler handler) 
    { 
     mSurfaceHolder = sHolder; 
     mHandler = handler; 
     mContext = context; 
     mActivity = (GameScreenActivity) context; 

     parachuters = new ArrayList<Parachuter>(); 
     parachuter = BitmapFactory.decodeResource(getResources(), R.drawable.parachuteman); 
     black = new Paint(); 
     black.setStyle(Paint.Style.FILL); 
     black.setColor(Color.WHITE); 

     running = true; 

     // This equates to 26 frames per second. 
     frameRate = (long) (1000/26); 
     loading = true; 
    } 

    @Override 
    public void run() 
    { 
     while (running) 
     { 
      Canvas c = null; 
      try 
      { 
       c = mSurfaceHolder.lockCanvas(); 

       synchronized (mSurfaceHolder) 
       { 
        long start = System.currentTimeMillis(); 
        doDraw(c); 
        long diff = System.currentTimeMillis() - start; 

        if (diff < frameRate) 
         Thread.sleep(frameRate - diff); 
       } 
      } catch (InterruptedException e) 
      { 
      } 
      finally 
      { 
       if (c != null) 
       { 
        mSurfaceHolder.unlockCanvasAndPost(c); 
       } 
      } 
     } 
    } 

    protected void doDraw(Canvas canvas) 
    { 
     canvas.drawRect(0, 0, canvas.getWidth(), canvas.getHeight(), black); 
     canvasGetWidth = canvas.getWidth(); 

     //Draw 
     for (int i = 0; i < parachuters.size(); i++) 
     { 
      canvas.drawBitmap(parachuter, parachuters.get(i).getX(), parachuters.get(i).getY(), null); 
      parachuters.get(i).tick(); 
     } 

     //Remove 
     for (int i = 0; i < parachuters.size(); i++) 
     { 
     if (parachuters.get(i).getY() > canvas.getHeight()) { 
      parachuters.remove(i); 
      onPlaySound(); 
      onMethod(); 
      checkLivesLeftValue(); 
     } 
    } 
    } 


    public void onPlaySound() 
    { 
     try { 
     mp1 = MediaPlayer.create(getContext(), R.raw.bombsound); 
     mp1.start(); 
     } catch (Exception e) { 
      e.printStackTrace(); 
      mp1.release(); 
     } 
    } 

    public void onMethod() { 
     Toast.makeText(getContext(), "You lost!", 15).show(); 
    } 

    private void checkLivesLeftValue() { 
     // TODO Auto-generated method stub 
     if (livesLeftValue == 3) { 
      //Message to display: "You lost!" 
      onMethod(); 
     } 
     else { 
      livesLeftValue = livesLeftValue + 1; 
     } 
    } 

    public boolean onTouchEvent(MotionEvent event) 
    { 
     if (event.getAction() != MotionEvent.ACTION_DOWN) 
      return false; 
     float x1 = event.getX(); 
     float y1 = event.getY(); 

     initiateDrawParachuters(); 

     return true; 
    } 

    public void initiateDrawParachuters() 
    { 
     drawParachuter1(); 
    } 

    private void drawParachuter1() { 
     // TODO Auto-generated method stub 
     //Parachuter nr. 1 
     x = 68; 
     y = 40; 

     Parachuter p = new Parachuter(x, y); 
     parachuters.add(p); 
     drawParachuter2(); 
    } 

    private void drawParachuter2() { 
     // TODO Auto-generated method stub 
     //Parachuter nr. 2 
     x = 100; 
     y = 80; 

     Parachuter p = new Parachuter(x, y); 
     parachuters.add(p); 
     drawParachuter3(); 
    } 

    private void drawParachuter3() { 
     // TODO Auto-generated method stub 
     //Parachuter nr. 3 
     x = 150; 
     y = 120; 

     Parachuter p = new Parachuter(x, y); 
     parachuters.add(p); 
     drawParachuter4(); 
    } 

    private void drawParachuter4() { 
     // TODO Auto-generated method stub 
     //Parachuter nr. 4 
     x = 170; 
     y = 150; 

     Parachuter p = new Parachuter(x, y); 
     parachuters.add(p); 
     drawParachuter5(); 
    } 

    private void drawParachuter5() { 
     // TODO Auto-generated method stub 
     //Parachuter nr. 5 
     x = 180; 
     y = 170; 

     Parachuter p = new Parachuter(x, y); 
     parachuters.add(p); 
     drawParachuter6(); 
    } 

    private void drawParachuter6() { 
     // TODO Auto-generated method stub 
     //Parachuter nr. 6 
     x = 200; 
     y = 180; 

     Parachuter p = new Parachuter(x, y); 
     parachuters.add(p); 
    } 

    public void drawParachuters() 
    { 
      Parachuter p = new Parachuter(x, y); 
      parachuters.add(p); 
      Toast.makeText(getContext(), "x=" + x + " y=" + y, 15).show(); 
    } 

    public void setRunning(boolean bRun) 
    { 
     running = bRun; 
    } 

    public boolean getRunning() 
    { 
     return running; 
    } 
} 

/** Handle to the application context, used to e.g. fetch Drawables. */ 
private Context mContext; 

/** Pointer to the text view to display "Paused.." etc. */ 
private TextView mStatusText; 

/** The thread that actually draws the animation */ 
private ExampleThread eThread; 

public ExampleView(Context context) 
{ 
    super(context); 

    // register our interest in hearing about changes to our surface 
    SurfaceHolder holder = getHolder(); 
    holder.addCallback(this); 

    // create thread only; it's started in surfaceCreated() 
    eThread = new ExampleThread(holder, context, new Handler() 
    { 
     @Override 
     public void handleMessage(Message m) 
     { 
      // mStatusText.setVisibility(m.getData().getInt("viz")); 
      // mStatusText.setText(m.getData().getString("text")); 
     } 
    }); 

    setFocusable(true); 
} 

@Override 
public boolean onTouchEvent(MotionEvent event) 
{ 
    return eThread.onTouchEvent(event); 
} 

public ExampleThread getThread() 
{ 
    return eThread; 
} 

@Override 
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) 
{ 
    // TODO Auto-generated method stub 
} 

public void surfaceCreated(SurfaceHolder holder) 
{ 
    if (eThread.getState() == Thread.State.TERMINATED) 
    { 
     eThread = new ExampleThread(getHolder(), getContext(), getHandler()); 
     eThread.start(); 
    } 
    else 
    { 
     eThread.start(); 
    } 
} 

@Override 
public void surfaceDestroyed(SurfaceHolder holder) 
{ 
    boolean retry = true; 
    eThread.setRunning(false); 

    while (retry) 
    { 
     try 
     { 
      eThread.join(); 
      retry = false; 
     } 
     catch (InterruptedException e) 
     { 
     } 
    } 
} 
} 

Und das ist meine logcat Ausgabe:

03-24 16:32:59.442: W/dalvikvm(363): threadid=7: thread exiting with uncaught exception (group=0x4001d800) 
03-24 16:32:59.641: E/AndroidRuntime(363): FATAL EXCEPTION: Thread-8 
03-24 16:32:59.641: E/AndroidRuntime(363): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 
03-24 16:32:59.641: E/AndroidRuntime(363): at android.os.Handler.<init>(Handler.java:121) 
03-24 16:32:59.641: E/AndroidRuntime(363): at android.widget.Toast.<init>(Toast.java:68) 
03-24 16:32:59.641: E/AndroidRuntime(363): at android.widget.Toast.makeText(Toast.java:231) 
03-24 16:32:59.641: E/AndroidRuntime(363): at com.mysoftwaremobileapps.ParachuteHunter.ExampleView$ExampleThread.onMethod(ExampleView.java:135) 
03-24 16:32:59.641: E/AndroidRuntime(363): at com.mysoftwaremobileapps.ParachuteHunter.ExampleView$ExampleThread.doDraw(ExampleView.java:116) 
03-24 16:32:59.641: E/AndroidRuntime(363): at com.mysoftwaremobileapps.ParachuteHunter.ExampleView$ExampleThread.run(ExampleView.java:79) 
03-24 16:33:03.842: I/Process(363): Sending signal. PID: 363 SIG: 9 

Answer 1

Du einen Toast von Thema zu schaffen, die nicht einem Looper an sie gebunden ist, besitzt. Die einfachste Lösung besteht darin, einen Toast aus einem UI-Thread zu erstellen, der Looper standardmäßig enthält.

Sie haben auch bereits einen Handler, der in einem View-Konstruktor erstellt wird. Sie können diesen Handler verwenden, um einige Runnable in UI-Threads zu posten und dort Toast zu erstellen.

public void onMethod() { 
    mHandler.post(new Runnable() { 
     @Override 
     public void run() { 
      Toast.makeText(getContext(), "You lost!", 15).show(); 
     } 
    }); 
}