Développement Android: 2d Graphic Transparent?

Question

Est-il possible de dessiner une image lors de contact et un BG transparent, donc je vois mon homesceen avec ceci:

android:theme="@android:style/Theme.Translucent.NoTitleBar" 

Et voici mon projet jusqu'à présent:

import java.util.ArrayList; 



import android.app.Activity; 
import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Bitmap.Config; 
import android.os.Bundle; 
import android.view.Display; 
import android.view.MotionEvent; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.view.Window; 
import android.view.WindowManager; 
import android.os.Bundle; 


public class main extends Activity { 
    private Panel mG; 


@Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     requestWindowFeature(Window.FEATURE_NO_TITLE); 
     // setContentView(new Panel(this)); 
     setContentView(R.layout.main); 

     mG = new Panel(this); 
     setContentView(mG); 
    } 

    class Panel extends SurfaceView implements SurfaceHolder.Callback { 
     private TutorialThread _thread; 
     private ArrayList<GraphicObject> _graphics = new ArrayList<GraphicObject>(); 

     public Panel(Context context) { 
      super(context); 
      getHolder().addCallback(this); 
      _thread = new TutorialThread(getHolder(), this); 
      setFocusable(true); 
     } 

     @Override 
     public boolean onTouchEvent(MotionEvent event) { 
      synchronized (_thread.getSurfaceHolder()) { 
       if (event.getAction() == MotionEvent.ACTION_DOWN) { 
        GraphicObject graphic = new GraphicObject(BitmapFactory.decodeResource(getResources(), R.drawable.myicon)); 
        graphic.getCoordinates().setX((int) event.getX() - graphic.getGraphic().getWidth()/2); 
        graphic.getCoordinates().setY((int) event.getY() - graphic.getGraphic().getHeight()/2); 
        _graphics.add(graphic); 
       } 
       return true; 
      } 
     } 

     @Override 
     public void onDraw(Canvas canvas) { 
     Display display = ((WindowManager)getSystemService(WINDOW_SERVICE)).getDefaultDisplay(); 
     int height = display.getHeight(); // not exactly correct 
      int width = display.getWidth(); // not exactly correct 

     //Bitmap bitmap = Bitmap.createBitmap(width, height, Config.ALPHA_8);//Config.RGB_565); 



      //canvas.drawColor(Color.Transparent); 
      Bitmap bitmap; 
      GraphicObject.Coordinates coords; 
      for (GraphicObject graphic : _graphics) { 
       bitmap = graphic.getGraphic(); 
       coords = graphic.getCoordinates(); 
       canvas.drawBitmap(bitmap, coords.getX(), coords.getY(), null); 
      } 
     } 

     @Override 
     public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
      // TODO Auto-generated method stub 
     } 

     @Override 
     public void surfaceCreated(SurfaceHolder holder) { 
      _thread.setRunning(true); 
      _thread.start(); 
     } 

     @Override 
     public void surfaceDestroyed(SurfaceHolder holder) { 
      // simply copied from sample application LunarLander: 
      // we have to tell thread to shut down & wait for it to finish, or else 
      // it might touch the Surface after we return and explode 
      boolean retry = true; 
      _thread.setRunning(false); 
      while (retry) { 
       try { 
        _thread.join(); 
        retry = false; 
       } catch (InterruptedException e) { 
        // we will try it again and again... 
       } 
      } 
     } 
    } 

    class TutorialThread extends Thread { 
     private SurfaceHolder _surfaceHolder; 
     private Panel _panel; 
     private boolean _run = false; 

     public TutorialThread(SurfaceHolder surfaceHolder, Panel panel) { 
      _surfaceHolder = surfaceHolder; 
      _panel = panel; 
     } 

     public void setRunning(boolean run) { 
      _run = run; 
     } 

     public SurfaceHolder getSurfaceHolder() { 
      return _surfaceHolder; 
     } 

     @Override 
     public void run() { 
      Canvas c; 
      while (_run) { 
       c = null; 
       try { 
        c = _surfaceHolder.lockCanvas(null); 
        synchronized (_surfaceHolder) { 
         _panel.onDraw(c); 
        } 
       } finally { 
        // do this in a finally so that if an exception is thrown 
        // during the above, we don't leave the Surface in an 
        // inconsistent state 
        if (c != null) { 
         _surfaceHolder.unlockCanvasAndPost(c); 
        } 
       } 
      } 
     } 
    } 

    class GraphicObject { 
     /** 
     * Contains the coordinates of the graphic. 
     */ 
     public class Coordinates { 
      private int _x = 100; 
      private int _y = 0; 

      public int getX() { 
       return _x + _bitmap.getWidth()/2; 
      } 

      public void setX(int value) { 
       _x = value - _bitmap.getWidth()/2; 
      } 

      public int getY() { 
       return _y + _bitmap.getHeight()/2; 
      } 

      public void setY(int value) { 
       _y = value - _bitmap.getHeight()/2; 
      } 

      public String toString() { 
       return "Coordinates: (" + _x + "/" + _y + ")"; 
      } 
     } 

     private Bitmap _bitmap; 
     private Coordinates _coordinates; 

     public GraphicObject(Bitmap bitmap) { 
      _bitmap = bitmap; 
      _coordinates = new Coordinates(); 
     } 

     public Bitmap getGraphic() { 
      return _bitmap; 
     } 

     public Coordinates getCoordinates() { 
      return _coordinates; 
     } 
    } 
} 

Cependant l'arrière-plan est noir et je ne vois pas mon écran d'accueil (ou mon activité de fond)

Qu'est-ce que je fais mal?

// Votre ami!

Answer 1

Bon à voir quelqu'un est en train de lire mes tutoriels :)

Je ne sais pas s'il est possible de voir l'écran d'accueil à travers l'arrière-plan, mais peut-être vous jeter un oeil à ceci: How do I create a transparent Activity on Android?