Button1.Attributes.Add("onclick", "this.disabled=true;" + this.GetPostBackEventReference(this.Button1));
//.net 2.0以上
Button1.Attributes.Add("onclick", "this.disabled=true;" + this.ClientScript.GetPostBackEventReference(Button1, ""));
原文出至
http://www.cnblogs.com/chinafine/archive/2008/07/03/1234854.html