asp.net防止恶意刷新或多次点击按钮的方法

<asp:button runat="server" ID="btn" text="Button" OnClick="aa_Click" />

以下是引用片段：

public void page_load(Object obj,EventArgs e)

{

btn.Attributes.Add("onclick","state=true;");

StringBuilder sb=new StringBuilder();

sb.Append("if (!state) return;");

sb.Append("var button=document.getElementById(’btn’);");

sb.Append("button.value=’Please Wait...’;");

sb.Append("document.body.style.cursor=’wait’;");

sb.Append("button.disabled=true;");

string strScript="<script>";

strScript=strScript +"var state=false;";

//将函数绑定到页面的onbeforeunload事件:

strScript=strScript +"window.attachEvent(’onbeforeunload’,function(){" +sb.ToString()+ "});";

strScript=strScript +"</"+"script>";

Page.RegisterStartupScript("onbeforeunload",strScript);

}

protected void aa_Click(object sender, EventArgs e)

{

//模拟长时间的按钮处理

System.Threading.Thread.Sleep(2000);

Response.Write("<script>alert(’bbbbbb!!’);" + "</" + "script>");

}