您要完成什么?如果您使用Windows身份验证，则无需自己处理身份验证.如果要处理它，则必须将身份验证模式设置为表单"，并具有针对Web应用程序的适当配置设置.

What are you trying to accomplish? If you are using Windows authentication there is no need to handle authentication yourself. If you want to handle it you must set the authentication mode to Forms, and have the appropriate configuration settings for the web application.