http://www.cnblogs.com/WizardWu/archive/2010/02/04/1663127.html
2. windows phone 31 and siliverlight 31
http://www.jeffblankenburg.com/
水印文字和水印图片
http://www.cnblogs.com/X-Jonney/archive/2009/03/19/1416668.html
http://blog.csdn.net/hookyzlr/article/details/6068750