渐变背景

放在res/drawable下面就可以了

 

 

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
    <gradient android:startColor="#FF000000" android:endColor="#FFFFFFFF"
            android:angle="90"/>
    <gradient android:startColor="#FFFFFFFF" android:endColor="#FF000000"
            android:angle="90"/>
</shape>

 

 

 

 

 

 

其实就是一层蒙板

 

对应的java类LinearGradient

 

比如

 

LinearGradient shader = new LinearGradient(0 ,originalImage.getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x80ffffff, 0x00ffffff, TileMode.CLAMP);

 

 

 

感谢：http://blog.csdn.net/kenshintang1215/article/details/5810033