背景（图片）在画布上绘制，同时在上面

Question

@Override protected void onDraw(Canvas canvas) { 

     if (mBitmap != null) { 

      canvas.drawColor(0xFFAAAAAA); 

      canvas.drawBitmap(background,0,0,mBitmapPaint); 

      if(isRelevant){ 
       canvas.drawBitmap(mBitmapLast, 0,0, mBitmapLastPaint); 
      } 

      canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint); 
       canvas.drawPath(mPath, mPaint); 
     } 
    } 

路我已经试过周围的线路开关

canvas.drawColor(0xFFAAAAAA); 
       canvas.drawBitmap(background,0,0,mBitmapPaint); 

当canvas.drawColor(0xFFAAAAAA);是第二，我的路径将显示出来，当我画他们在屏幕。有没有办法让背景（位图）显示在画布路径下面？

Answer 1

尝试在你的路径的油漆设置Xfermode：

mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OVER)); // or DST_OVER 

，看到PorterDuff.Mode解释。