The important thing here is "ClassLibraryName" which is the assembly name for your class library. "/images/myimage.png" is the path to your image.
You can find out more about WPF pack URIs here: http://msdn.microsoft.com/en-us/library/aa970069.aspx
今天把Project中的图片删掉了。又用了同样的方法试了一下成功了。很无语。
编程序需要一点点耐心,还有不断积累。