Zeichnen von Bitmap (Pfeile) außerhalb des Kreises auf Leinwand in Android

Question

Ich habe gerade begonnen, einige benutzerdefinierte Ansichten in Android zu erstellen, aber ich habe Probleme beim Zeichnen von Bitmap (Pfeile) außerhalb des Kreises.

Hier ist mein Code:

Canvas osCanvas = new Canvas(windowFrame); // Create a canvas to draw onto the new image 
    RectF outerRectangle = new RectF(0, 0, getWidth(), getHeight()); 
    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); // Anti alias allows for smooth corners 
    paint.setColor(Color.parseColor("#FAFAFA")); // This is the color of your activity background 
    osCanvas.drawRect(outerRectangle, paint); 
    final Paint stroke = new Paint(); 

    //paint.setColor(Color.TRANSPARENT); // An obvious color to help debugging 
    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT)); // A out B http://en.wikipedia.org/wiki/File:Alpha_compositing.svg 
    float centerX = getWidth()/2; 
    float centerY = getHeight()/2; 
    double rad = Math.min(getWidth(), getHeight())/2.5 - menuInnerPadding; 
    float radius = (float) rad; 

    stroke.setColor(Color.parseColor("#999999")); 
    stroke.setStyle(Paint.Style.STROKE); 
    stroke.setAntiAlias(true); 
    stroke.setStrokeWidth(5f); 
    osCanvas.drawCircle(centerX , 
      centerY , radius - stroke.getStrokeWidth() +5f, stroke); 

    for(int i=0;i<elements.size();i++){ 
     double angle =0; 
     if(i==0){ 
      angle = startAngle; 
     }else{ 
      angle = startAngle+(i * ((2 * Math.PI)/elements.size())); 
     } 
     elements.get(i).x = (int) (centerX + Math.cos(angle)*(radius)); 
     elements.get(i).y = (int) (centerY + Math.sin(angle)*(radius)); 
     float ang = (float) Math.cos(angle)*(radius); 
     Path path = new Path(); 
     path.addCircle(elements.get(i).x,elements.get(i).y, radius, Path.Direction.CW); 
     if(BLINKER_ID == i){ 
      if(blinkerPain != null){ 
       osCanvas.drawBitmap(elements.get(i).bitmap,elements.get(i).x,elements.get(i).y,blinkerPain); 
       blinkerPain = null; 
      } 
     }else{ 

      // here i am drawing the red arrows (bitmap images) But it's not fitting outside the circle. 
      osCanvas.drawBitmap(elements.get(i).bitmap,elements.get(i).x ,elements.get(i).y ,textPaint); 
     } 


    } 

Hier ist mein Ausgang

Ich denke Problem mit der Polsterung ist.

Answer 1

Ich habe Code neu schreiben. Sie sollten diesen Code überprüfen.

@Override 
protected void onDraw(Canvas canvas) { 
    Paint paint = new Paint(); 
    paint.setColor(Color.BLUE); 
    paint.setStrokeWidth(2); 
    paint.setStyle(Paint.Style.STROKE); 
    canvas.drawColor(Color.WHITE); 

    float x = 400; 
    float y = 400; 
    float r = 200; 

    canvas.drawCircle(x , y , r , paint); 

    Bitmap icon = BitmapFactory.decodeResource(getContext().getResources(), R.mipmap.ic_launcher); 

    int length = 8; 

    float radian = (float)(Math.PI * 2f)/length; 

    for(int i = 0; i<length; i++) { 
     drawBitmap(canvas , icon , x , y , r, radian * i); 
    } 
} 

private void drawBitmap(Canvas canvas, Bitmap bitmap, float pivotX, float pivotY, float radius, float radian) { 
    Matrix m = new Matrix(); 
    m.postTranslate(-bitmap.getWidth()/2 , -bitmap.getHeight()/2); 
    m.postRotate((float)(radian * 180/Math.PI) + 90); 

    float drawHeight = radius + (bitmap.getHeight()/2); 

    m.postTranslate(((float)Math.cos(radian) * drawHeight) + pivotX 
      , ((float)Math.sin(radian) * drawHeight) + pivotY); 

    canvas.drawBitmap(bitmap , m , null); 
}