android如何繪製半透明的畫布上的位圖

Question

我試圖修改一個Paint變量，但一直不成功 - 我怎樣才能使一個位圖顯示「半透明」？

Answer 1

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); 

Answer 2

Paint p = new Paint(); 
p.setAlpha(70); 

Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper); 
canvas.drawBitmap(image, xPosition, yPosition, p);