Fatal signal 11 (SIGSEGV), code 1, erreur addr 0xc0 dans tid 20706 en essayant de dessiner bitmap sur le canevas

Question

J'essaye de dessiner une image bitmap sur le canevas. Mais ce faisant, je reçois l'exception spécifiée ci-dessous.

10-10 11:29:18.592: A/libc(20706): Fatal signal 11 (SIGSEGV), code 1, fault addr 0xc0 in tid 20706 (apcanvasexample) 

Voici mon code.

public class MapView extends View implements IAsyncResponse { 
    private Path path; 
    private Paint paint; 

    private URL url; 

    private Bitmap bmp; 
    private Canvas canvas; 

    public MapView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     path = new Path(); 
     paint = new Paint(); 
     paint.setStyle(Paint.Style.STROKE); 
     paint.setColor(Color.RED); 
     paint.setStrokeWidth(10); 
     path.moveTo(0, 0); 

    } 

    @SuppressLint("DrawAllocation") 
    @Override 
    public void onDraw(Canvas canvas) { 
     this.canvas = canvas; 

      path.lineTo(currentX, currentY); 
      canvas.drawPath(path, paint); 

     new DownloadImageTask(canvas, this) 
       .execute("http://<ip>:<port>/map/download/image?imageType=jpg&mapId=1"); 
    } 

    private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> { 
     IAsyncResponse delegate; 
     Canvas canvas; 

     public DownloadImageTask(Canvas canvas, IAsyncResponse delegate) { 
      this.canvas = canvas; 
      this.delegate = delegate; 
     } 

     protected Bitmap doInBackground(String... urls) { 
      String urldisplay = urls[0]; 
      Bitmap mIcon11 = null; 
      try { 
       InputStream in = new java.net.URL(urldisplay).openStream(); 
       mIcon11 = BitmapFactory.decodeStream(in); 
      } catch (Exception e) { 
       Log.e("Error", e.getMessage()); 
       e.printStackTrace(); 
      } 
      return mIcon11; 
     } 

     protected void onPostExecute(Bitmap result) { 
      delegate.processFinished(result); 
     } 
    } 

    @Override 
    public void processFinished(Bitmap bmp) { 
     canvas.drawBitmap(bmp, new Rect(100,100,150,150), new Rect(0,0,50,50) , null); 
    } 

} 

Answer 1

Vous devez désactiver l'accélération matérielle pour cette vue.

yourview.setLayerType(View.LAYER_TYPE_SOFTWARE, null); 

https://developer.android.com/guide/topics/graphics/hardware-accel.html#controlling

Answer 2

public class MapView 
     extends View 
     implements IAsyncResponse { 

    public MapView(Context context) { 
     super(context); 
     init(); 
    } 

    public MapView(
      Context context, 
      AttributeSet attrs) { 
     super(context, attrs); 
     init(); 

    } 

    public MapView(
      Context context, 
      AttributeSet attrs, 
      int defStyleAttr) { 
     super(context, attrs, defStyleAttr); 
     init(); 
    } 

    private Path path; 
    private Paint paint; 

    private URL url; 

    private Bitmap bmp; 

    // use common init method for initialization, which is called from all the constructors 
    void init() { 
     path = new Path(); 
     paint = new Paint(); 
     paint.setStyle(Paint.Style.STROKE); 
     paint.setColor(Color.RED); 
     paint.setStrokeWidth(10); 
     path.moveTo(0, 0); 

     // start the downloader task only once and not within onDraw callback 
     // please note that, reference to canvas is not hold 
     new DownloadImageTask(this).execute("my/image/url"); 
    } 

    @Override 
    public void onDraw(Canvas canvas) { 
     // all your other drawing logic goes here 
     if (null != bmp) { 
      canvas.drawBitmap(bmp, new Rect(100, 100, 150, 150), new Rect(0, 0, 50, 50), null); 
     } 
    } 

    private class DownloadImageTask 
      extends AsyncTask<String, Void, Bitmap> { 
     IAsyncResponse delegate; 

     public DownloadImageTask(
       IAsyncResponse delegate) { 
      this.delegate = delegate; 
     } 

     protected Bitmap doInBackground(String... urls) { 
      String urldisplay = urls[0]; 
      Bitmap mIcon11 = null; 
      try { 
       InputStream in = new java.net.URL(urldisplay).openStream(); 
       mIcon11 = BitmapFactory.decodeStream(in); 
      } catch (Exception e) { 
       Log.e("Error", e.getMessage()); 
       e.printStackTrace(); 
      } 
      return mIcon11; 
     } 

     protected void onPostExecute(Bitmap result) { 
      // you probably don't even need delegate. But I have kept it for consistency. 
      // alternatively you can remove this interface and do - 
      //   MapView.this.bmp = bmp; 
      //   invalidate(); 

      delegate.processFinished(result); 
     } 
    } 

    @Override 
    public void processFinished(Bitmap bmp) { 
     this.bmp = bmp; 
     invalidate(); 
    } 

}