我试图修改一个画图的变量，但并不成功 - 我怎样才能使一个位图出现半透明

  canvas.drawColor（Color.WHITE）;。BitmapDrawable BD =（BitmapDrawable）getResources（）getDrawable（R.drawable.loading）;位图BM = bd.getBitmap（）;涂料粉刷=新的油漆（）;paint.setAlpha（60）; //你可以在这里设置您的透明值canvas.drawBitmap（BM，0，0，油漆）; 

I have tried to modify a Paint variable, but have been unsuccessful - how can I make a bitmap appear "semi-transparent"?

canvas.drawColor(Color.WHITE);   
BitmapDrawable bd = (BitmapDrawable) getResources().getDrawable(R.drawable.loading);    
Bitmap bm = bd.getBitmap();    
Paint paint = new Paint();    
paint.setAlpha(60);                             //you can set your transparent value here    
canvas.drawBitmap(bm, 0, 0, paint);