解决方法一：
.Framework2.0中才有的button属性：<asp:button id="btnSubmit" onclick="btnSubmit_Click" runat="server" OnClientClick="this.disabled=true;this.form.submit();" UseSubmitBehavior="False" />
解决重复提交：OnClientClick="this.disabled=true;this.form.submit();" UseSubmitBehavior="False"
解决方法二：
this.btnSubmit.Attributes["onclick"] = this.GetPostBackEventReference(this.btnSubmit) + ";this.disabled=true;"; //防止重复提交