感觉这种最好用：

public void showMessage(string str_Message)        {            ClientScript.RegisterStartupScript(this.GetType(), "结果", "alert('" + str_Message + "');", true);            // Define the name and type of the client scripts on the page.            String csname1 = "PopupScript";            String csname2 = "ButtonClickScript";            Type cstype = this.GetType();            ClientScriptManager cs = Page.ClientScript;            if (!cs.IsStartupScriptRegistered(cstype, csname1))            {                String cstext1 = "alert('Hello World');";                cs.RegisterStartupScript(cstype, csname1, cstext1, true);            }            if (!cs.IsClientScriptBlockRegistered(cstype, csname2))            {                System.Text.StringBuilder cstext2 = new System.Text.StringBuilder();                cstext2.Append("");            //Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "tishi","");            //ClientScriptManager scriptManager =((System.Web.UI.Page)System.Web.HttpContext.Current.Handler).ClientScript;            //scriptManager.RegisterStartupScript(typeof(string), "", "alert('str_Message');", true);            //scriptManager.RegisterStartupScript(typeof(string), "", "alert('str_Message');self.location='redirect'", true);        }

 

 

 

原文转载：http://www.cnblogs.com/luqian5588/p/3228225.html

 

 

 

1.后台弹出提示信息方法

Response.Write("<scripttype="text/javascript">alert('你所查询的数据不存在！');</script>");

//弹出提示信息，但页面空白 Page.RegisterClientScriptBlock("tishi", "<scripttype="text/javascript">alert('你所查询的数据不存在');</script>");

 

//弹出提示信息，但页面空白 Page.RegisterStartupScript("tishi", "<scripttype="text/javascript">alert('你所查询的数据不存在');</script>");//已过期，

 

//弹出提示信息，页面不空白 ClientScript.RegisterClientScriptBlock(this.GetType(), "tishi","<script type="text/javascript">alert('你所查询的数据不存在！');</script>");

 

//弹出提示信息，但页面空白 ClientScript.RegisterStartupScript(this.GetType(), "tishi","<script type="text/javascript">alert('你所查询的数据不存在！');

 

 

</script>");

 

//弹出提示信息，页面不空白

//在vs2005中 需要引入System.Web.Extensions.dll ScriptManager.RegisterClientScriptBlock(this.btnTiShi, typeof(Button),"tishi", "alert('你所查询的数据不存在！');", true);

 

//弹出提示信息，但页面空白 ScriptManager.RegisterClientScriptBlock(this, this.GetType(),"tishi", "alert('你所查询的数据不存在！');", true);

 

//弹出提示信息，但页面空白,this表示page ScriptManager.RegisterStartupScript(this.btnTiShi, typeof(Button),"tishi", "alert('你所查询的数据不存在！');", true);

 

//弹出提示信息，页面不空白 ScriptManager.RegisterStartupScript(Page,typeof(Page), "tishi","alert('你所查询的数据不存在！');", true);

 

//弹出提示信息，页面不空白 ScriptManager.RegisterStartupScript(this, typeof(_Default), "tishi",script, true);

 

//弹出提示信息，页面不空白,this表示page

 

//后台获得confirm返回值，并有选择的执行语句块 C#端： protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { this.btnTiShi.Attributes.Add("onclick","tishi()"); } }

protected voidbtnTiShi_Click(object sender, EventArgs e) { if (this.hidevalue.Value == "1") { Response.Write("success"); } else { Response.Write("failue"); } }

 

JS端： <script type="text/javascript"> function tishi() { if(confirm('你确定要删除吗？')) { document.getElementByIdx_x('hidevalue').value='1'; //window.location.href=window.location.href; } else { document.getElementByIdx_x('hidevalue').value='0'; } } </script>