我在桌面上成功构建了.dll源代码但是当我尝试在WP7项目上引用dll时,我收到以下错误：

Reference cannot be added to c:\path\to\my.dll because it was not built using
the Windows Phone runtime. Windows Phone projects will work only with
Windows Phone assemblies.

有没有一种使用Windows Phone运行时构建它的简单方法？