ColorMatrixColorFilter颜色过滤（离线用户的灰色头像处理）

Android的图片资源默认是静态的，单实例；如果两个IM好友的头像一样，最简单的都是用的软件自带头像，有一个在线，一个离线，直接改变头像的灰度，则两个用户的头像都会变灰或者在线，答案是：Drawable.mutate()。 

Java代码 

Drawable mDrawable = context.getResources().getDrawable(R.drawable.face_icon);   
//Make this drawable mutable.   
//A mutable drawable is guaranteed to not share its state with any other drawable.   
mDrawable.mutate();   
ColorMatrix cm = new ColorMatrix();   
cm.setSaturation(0);   
ColorMatrixColorFilter cf = new ColorMatrixColorFilter(cm);   
mDrawable.setColorFilter(cf);  

转自：http://gundumw100.iteye.com/blog/1126129