利用自定义事件结合ModalPopup写一个通用的MsgBox类

--ModalPopup.cs
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Web.UI.WebControls;
using AjaxControlToolkit;

namespace ajaxcs
{
    public class ModalPopup
    {
        public delegate void OnMsgBoxEventHandler(string ReturnValue);
        public class MsgBox
        {
                private Button CancelButton;
                private HiddenField HiddenField1;
                private ModalPopupExtender ModalPopupExtender1;
                private Panel MsgBoxPanel;
                private Label MsgLabel;
                private Button OkButton;
                private Label TitleLabel;

                public event OnMsgBoxEventHandler OnMsgBox;

                public MsgBox()
                {

                    this.HiddenField1 = new HiddenField();
                    this.ModalPopupExtender1 = new ModalPopupExtender();
                }

                public void Initial(Panel MsgBoxPanel, Label MsgLabel, Label TitleLabel, Button OkButton, Button CancelButton)
                {
                    this.ModalPopupExtender1.ID = MsgBoxPanel.ID + "_ModalPopupExtender1";
                    this.HiddenField1.ID = MsgBoxPanel.ID + "_HiddenField1";
                    MsgBoxPanel.Parent.Controls.Add(this.HiddenField1);
                    MsgBoxPanel.Parent.Controls.Add(this.ModalPopupExtender1);
                    this.ModalPopupExtender1.TargetControlID = this.HiddenField1.ClientID;
                    this.ModalPopupExtender1.PopupControlID = MsgBoxPanel.ID;
                    this.MsgBoxPanel = MsgBoxPanel;
                    this.MsgLabel = MsgLabel;
                    this.TitleLabel = TitleLabel;
                    this.OkButton = OkButton;
                    this.CancelButton = CancelButton;
                    if (MsgBoxPanel.Page.Request.Form["__EVENTTARGET"] == this.HiddenField1.ClientID)
                    {
                        if (OnMsgBox != null)
                            OnMsgBox(MsgBoxPanel.Page.Request.Form[this.HiddenField1.ClientID]);
                    }
                }
 
                public void Show(string msg, [Optional, DefaultParameterValue("询问窗口")] string title, [Optional, DefaultParameterValue("")] string ModalBackgroundStyle, [Optional, DefaultParameterValue(100)] int x, [Optional, DefaultParameterValue(100)] int y)
                {
                    string js = "<script>";
                    js = (((js + "function _onMsgBoxOK(v){") + "$get('" + this.HiddenField1.ClientID + "').value=v;") + this.MsgBoxPanel.Page.ClientScript.GetPostBackEventReference(this.MsgBoxPanel.Page.FindControl(this.ModalPopupExtender1.TargetControlID), "")) + "}" + "</script>";
                    this.MsgBoxPanel.Page.ClientScript.RegisterStartupScript(typeof(string), "showModalWindow_MsgBox", js);
                    this.ModalPopupExtender1.TargetControlID = this.HiddenField1.ClientID;
                    this.ModalPopupExtender1.PopupControlID = this.MsgBoxPanel.ID;
                    this.ModalPopupExtender1.BackgroundCssClass = ModalBackgroundStyle;
                    this.ModalPopupExtender1.DropShadow = true;
                    this.ModalPopupExtender1.OkControlID = this.OkButton.ID;
                    this.ModalPopupExtender1.OnOkScript = "_onMsgBoxOK(true)";
                    this.ModalPopupExtender1.OnCancelScript = "_onMsgBoxOK(false)";
                    this.ModalPopupExtender1.CancelControlID = this.CancelButton.ID;
                    this.ModalPopupExtender1.PopupDragHandleControlID = this.TitleLabel.ID;
                    this.ModalPopupExtender1.X = x;
                    this.ModalPopupExtender1.Y = y;
                    this.ModalPopupExtender1.OkControlID = this.OkButton.ID;
                    this.MsgLabel.Text = msg;
                    this.TitleLabel.Text = title;
                    this.ModalPopupExtender1.Show();
                }

               
        }
    }
}
--调用后台代码

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using ajaxcs;

namespace ajaxcs
{
    public partial class _Default : System.Web.UI.Page
    {
        ModalPopup.MsgBox MsgBox1 = new ModalPopup.MsgBox();
        protected void Page_Load(object sender, EventArgs e)
        {
            MsgBox1.OnMsgBox += new ModalPopup.OnMsgBoxEventHandler(MsgBox1_OnMsgBox);
            MsgBox1.Initial(this.Panel1, this.Label2, this.LBL_Title, this.btn_OK, this.btn_Cancel);
           

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            MsgBox1.Show(this.txb_body.Text, this.txb_title.Text, "modalbackground", 120, 100);
        }
        protected void MsgBox1_OnMsgBox(string ReturnValue)
        {
            Response.Write(ReturnValue);
        }
    }
}

--前台代码

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>未命名页面</title>
    <style type="text/css">
.modalbackground
{
    border: 1px solid #2F4F4F;
    color: white;
    background-color: #000000;
    font-weight: bold;
    cursor: not-allowed;
    filter: Alpha(opacity=40);
}
</style>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        ModalPopup - MsgBox(用户输入的值可返回值给后端)<br />
        <br />
        范例：<br />
        <br />
        标题：<asp:TextBox ID="txb_title" runat="server">询问：</asp:TextBox><br />
        内文：<asp:TextBox ID="txb_body" runat="server">您确定要这怎么做?</asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="ShowByPostback"
            onclick="Button1_Click" /><br />
        <br />
        <asp:Panel ID="Panel1" runat="server" BackColor="WhiteSmoke" BorderColor="#0000C0"
            BorderStyle="Solid" BorderWidth="1px" Height="168px" HorizontalAlign="Center"
            Style="display: none" Width="296px">
            <span style="color: #ffffff"></span>
            <asp:Label ID="LBL_Title" runat="server" BackColor="Blue" Font-Bold="True" ForeColor="White"
                Style="text-align: left" Text="标题" Width="100%"></asp:Label><br />
            <br />
            <asp:Label ID="Label2" runat="server" ForeColor="Black" Height="72px" Text="Label"
                Width="100%"></asp:Label><br />
            &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;
            <table style=" 100%">
                <tr>
                    <td align="right">
                        <asp:Button ID="btn_OK" runat="server" Text="确定" />
                        <asp:Button ID="btn_Cancel" runat="server" Text="取消" /></td>
                </tr>
            </table>
            &nbsp;&nbsp;
        </asp:Panel>
   
    </div>
    </form>
</body>
</html>