我认为您想显示Window的消息框，它''会像这样

I think you want to show Window''s Message Box,it''ll be like this

System.Windows.Form.MessageBox.Show()

和JS警报会像
Reponse.Write("alert(" Hello)");

and JS alert will be like
Reponse.Write("alert(''Hello'')");

亲爱的朋友，

请通过此链接解决您的问题:-

ASP.Net不允许您像在C#Windows应用程序中一样显示消息框.在此处或Ajax中使用JavaScript警报框.

http://***.com/questions/4779576/how-to-display-windows-form-messagebox-in-asp-net-web-application [

Dear Friend,

Please follow this link for your problem:-

ASP.Net doesn''t allow you to show message boxes like in C# windows application. Use javascript alert boxes here or ajax.

http://***.com/questions/4779576/how-to-display-windows-form-messagebox-in-asp-net-web-application[^]

Always do some google search first.

Thanks

JavaScript和jQuery是连击选项

但是在c#中尝试一下

JavaScript and jQuery is batter option

but try this in c#

string myStringVariable = string.Empty;

myStringVariable = "Welcome";


ClientScript.RegisterStartupScript(this.GetType(), "myalert", "alert('" + myStringVariable + "');", true);

看看这个:

一个简单的ASP.NET服务器控件:消息框&确认框 [ ^ ]

and have a look at this:

A Simple ASP.NET Server Control: Message Box & Confirmation Box[^]