安卓设置imageview变暗的效果，类似于qq离线状态

private Bitmap getDarker(Drawable d){

BitmapDrawable drawable =(BitmapDrawable)d;

Bitmap origin = drawable.getBitmap();

int width = origin.getWidth();

int height = origin.getHeight();

Bitmap background =Bitmap.createBitmap(width, height, Config.ARGB_8888);

Canvas canvas=new Canvas(background);

canvas.drawBitmap(origin, 0, 0, new Paint());

Paint p1=new Paint();

p1.setAlpha(75);

canvas.drawRect(0, 0, width, height, p1);

return background;

}

先通过inmageview.getDrawable()获得drawable，然后开始应用就可以了，也可以通过设置setColorFilter（）来达到效果