解决UpdatePanel无法直接弹出窗口的问题

/// <summary>
    /// 自定义弹出窗口内容
    /// </summary>
    /// <param name="msg"></param>
    public static void AjaxShowWindows(string msg)
    {
        //myContext.Response.Write("<script>彈出窗口代碼(wondows.open(XXX));</script>");
        string script="彈出窗口代碼(wondows.open(XXX));"; //注意彈出窗口的ID，最好使用隨機，否則只能彈出一次
        ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowWindows", script, true);
    }

==========參考代碼===========

using System;
using System.Collections.Generic;
using System.Text;

using System.Web;
using System.Web.UI;

public class ShowMessage
{
    /// <summary>
    /// 自定义弹出窗口内容，不跳转
    /// </summary>
    /// <param name="page"></param>
    /// <param name="msg"></param>
    public static void Show(System.Web.UI.Page page, string msg)
    {
        page.ClientScript.RegisterStartupScript(page.GetType(), "ShowMessage", "alert('" + msg + "');", true);
    }
    /// <summary>
    /// 自定义弹出窗口内容，并跳转
    /// </summary>
    /// <param name="page"></param>
    /// <param name="msg"></param>
    /// <param name="returnUrl"></param>
    public static void Show(System.Web.UI.Page page, string msg, string returnUrl)
    {
        page.ClientScript.RegisterStartupScript(page.GetType(), "ShowMessage", "alert('" + msg + "');window.location.href='" + returnUrl + "';", true);
    }
    /// <summary>
    /// 自定义弹出窗口内容，并跳转
    /// </summary>
    /// <param name="page"></param>
    /// <param name="msg"></param>
    /// <param name="returnUrl"></param>
    public static void Show(System.Web.UI.Page page, string msg, string trueReturnUrl, string falseReturnUrl)
    {
        page.ClientScript.RegisterStartupScript(page.GetType(), "ShowMessage", "if(confirm('" + msg + "')){javascript:location='" + trueReturnUrl + "';}else{javascript:location='" + falseReturnUrl + "';}", true);
    }

    /// <summary>
    /// 自定义弹出窗口内容
    /// </summary>
    /// <param name="msg"></param>
    public static void AjaxShow(string msg)
    {
        //myContext.Response.Write("<script>alert('" + msg + "');</script>");
        ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowMessage", "alert('" + msg + "');", true);
    }
    /// <summary>
    /// 自定义弹出窗口内容并直接转向一个新的页面
    /// </summary>
    /// <param name="msg"></param>
    /// <param name="url"></param>
    public static void AjaxShow(string msg, string url)
    {
        //myContext.Response.Write("<script>alert('" + msg + "');javascript:location='"+Url+"';</script>");
        ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowMessage", "alert('" + msg + "');javascript:location='" + url + "';", true);

    }
    /// <summary>
    /// 自定义弹出窗口内容并选择是直接转向，还是提示转向一个新的页面
    /// </summary>
    /// <param name="msg"></param>
    /// <param name="isreturn"></param>
    /// <param name="url"></param>
    public static void AjaxShow(string msg, bool isreturn, string url)
    {
        if (!isreturn)
        {
            //myContext.Response.Write("<script>alert('" + msg + "');javascript:location='"+Url+"';</script>");
            ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowMessage", "alert('" + msg + "');javascript:location='" + url + "';", true);
        }
        else
        {
            //myContext.Response.Write("<script>alert('" + msg + "');javascript:location='"+Url+"';</script>");
            ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowMessage", "if(confirm('" + msg + "')){javascript:location='" + url + "';}", true);
        }

    }
    /// <summary>
    /// 自定义弹出窗口内容，自定义是否关闭当前页面
    /// </summary>
    /// <param name="msg"></param>
    /// <param name="close"></param>
    public static void AjaxShow(string msg, bool close)
    {
        if (close)
        {
            // myContext.Response.Write("<script>alert('" + msg + "');javascript:window.close();</script>");
            ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowMessage", "alert('" + msg + "');javascript:window.close();", true);
        }
        else
        {
            //myContext.Response.Write("<script>alert('" + msg + "');</script>");
            ScriptManager.RegisterStartupScript((System.Web.UI.Page)HttpContext.Current.CurrentHandler, typeof(System.Web.UI.Page), "ShowMessage", "alert('" + msg + "');", true);
        }
    }
}

转贴自 http://kb.cnblogs.com/a/1336111/