我是把人家的考过来用的,这句不知错在哪了啊
this.BtnBack.Attributes[ "onclick "] = "self.location= 'FileList.aspx?ft= "+this.ViewState[ "FILETYPE "].ToString()+ " ';return false; ";
------解决方案--------------------------------------------------------
this.ViewState[ "FILETYPE "]
有值吗??
------解决方案--------------------------------------------------------
可能是因为this.ViewState[ "FILETYPE "]的值为null而使
this.ViewState[ "FILETYPE "].ToString()出错了.