ASP.NET整个Postback程序处理的过程
我们知道,无论是ASP.NET1.x, 2.0,甚至是以后的版本,ASP.NET最终Render到Client端通过浏览器浏览的都是一样:一个单纯的HTML。Client通过 Submit Form的方式将填入Form的数据提交给Server进行处理。我们现在来看看ASP.NET整个Postback程序处理的过程。
首先我们通过一个Sample来看ASP.NET如何处理一个通过Click一个Button引起的Postback。下面是Web Page的HTML:
- <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="_Default" %>- <!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 runat="server">
- <title>Test Page</title>
- </head>
- <body>
- <form id="form1" runat="server">
- <div>
- <asp:Label runat="server" ID="LabelMessage" ForeColor="red"></asp:Label>
- </div>
- <div>
- <asp:Button runat="server" ID="Button1" Text="Button1" OnClick="Button1_Click"
OnCommand="Button_Command" CommandArgument="Button1" />- <asp:Button runat="server" ID="Button2" Text="Button2" OnClick="Button2_Click"
OnCommand="Button_Command" CommandArgument="Button2" UseSubmitBehavior="false" />- <asp:Button runat="server" ID="Button3" Text="Button3" OnClick="Button3_Click"
OnCommand="Button_Command" CommandArgument="Button3" UseSubmitBehavior="false" />- </div>
- </form>
- </body>
- </html>
很简单,定义了3个Button,分别注册了他们的两个Event:Click和Command。3个Button的Command Event Hander是一样的:Button_Command,通过指定的CommandArgument来让Event Handler判断到底是哪个Button触发了Command Event。
下面是Code Behind:
- using System;
- using System.Data;
- using System.Configuration;
- 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;
- public partial class _Default : System.Web.UI.Page
- {
- protected void Page_Load(object sender, EventArgs e)
- {
- }
- protected void Button1_Click(object sender, EventArgs e)
- {
- string message = string.Format("The {0} event of {1} is fired", "Click", "Button1");
- this.LabelMessage.Text = message;
- }
- protected void Button2_Click(object sender, EventArgs e)
- {
- string message = string.Format("The {0} event of {1} is fired", "Click", "Button2");
- this.LabelMessage.Text = message;
- }
- protected void Button3_Click(object sender, EventArgs e)
- {
- string message = string.Format("The {0} event of {1} is fired", "Click", "Button3");
- this.LabelMessage.Text = message;
- }
- protected void Button_Command(object sender, CommandEventArgs e)
- {
- string message = string.Format("The {0} event of {1} is fired",
"Command", e.CommandArgument);- this.LabelMessage.Text += "; " + message;
- }
- }
以上是介绍ASP.NET整个Postback程序处理的过程。
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