给图片的边缘加上光晕

ImageView v = (ImageView)findViewById(R.id.image);//一定要给ImageView加上几个像素的Padding，要不然效果出来不了
Paint p= new Paint();
p.setColor(Color.RED);//红色的光晕
BitmapDrawable bd = (BitmapDrawable) v.getDrawable();
		Bitmap b = bd.getBitmap();
		Bitmap bitmap = Bitmap.createBitmap(bd.getIntrinsicWidth(), bd.getIntrinsicHeight(), Config.ARGB_8888);
		Canvas canvas = new Canvas(bitmap);
		canvas.drawBitmap(b.extractAlpha(), 0, 0, p);
		
		StateListDrawable sld = new StateListDrawable();
		sld.addState(new int[]{android.R.attr.state_pressed}, new BitmapDrawable(bitmap));
		
		v.setBackgroundDrawable(sld);

参考 http://gundumw100.iteye.com/blog/1205547#comments