ASP.NET Postback的Web Page生命周期
作者：佚名
本文介紹ASP.NET Postback，就得說Web Page生命周期，但是Web Page生命周期卻不是三言兩語就能夠說得清楚的，所以在這里單純站的編程的角度，撇開Web Page生命周期淺談Postback。
說道ASP.NET Postback，就得說Web Page生命周期，但是Web Page生命周期卻不是三言兩語就能夠說得清楚的，所以在這里單純站的編程的角度，撇開Web Page生命周期淺談Postback。
我們知道，無論是ASP.NET1.x,2.0，甚至是以后的版本，ASP.NET最終Render到Client端通過瀏覽器瀏覽的都是一樣：一個單純的HTML。Client通過Submit Form的方式將填入Form的數據提交給Server進行處理。我們現在來看看ASP.NET Postback程序處理的過程。
首先我們通過一個Sample來看ASP.NET如何處理一個通過Click一個Button引起的Postback。下面是Web Page的HTML：
- <%@PageLanguage="C#"AutoEventWireup="true"CodeFile="Default.
aspx.cs"Inherits="_Default"%>- <!DOCTYPEhtmlPUBLIC"-//W3C//DTDXHTML1.0Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">- <htmlxmlnshtmlxmlns="http://www.w3.org/1999/xhtml">
- <headrunatheadrunat="server">
- <title>TestPage</title>
- </head>
- <body>
- <formidformid="form1"runat="server">
- <div>
- <asp:Labelrunatasp:Labelrunat="server"ID="LabelMessage"ForeColor="red"></asp:Label>
- </div>
- <div>
- <asp:Buttonrunatasp:Buttonrunat="server"ID="Button1"Text="Button1"OnClick=
"Button1_Click"OnCommand="Button_Command"CommandArgument="Button1"/>- <asp:Buttonrunatasp:Buttonrunat="server"ID="Button2"Text="Button2"OnClick=
"Button2_Click"OnCommand="Button_Command"CommandArgument="Button2"UseSubmitBehavior="false"/>- <asp:Buttonrunatasp:Buttonrunat="server"ID="Button3"Text="Button3"OnClick=
"Button3_Click"OnCommand="Button_Command"CommandArgument="Button3"UseSubmitBehavior="false"/>- </div>
- </form>
- </body>
- </html>
很簡單，定義了3個Button，分別注冊了他們的兩個Event：Click和Command。3個Button的Command Event Hander是一樣的：Button_Command，通過指定的CommandArgument來讓Event Handler判斷到底是哪個Button觸發了Command Event。
下面是Code Behind：
- usingSystem;
- usingSystem.Data;
- usingSystem.Configuration;
- usingSystem.Web;
- usingSystem.Web.Security;
- usingSystem.Web.UI;
- usingSystem.Web.UI.WebControls;
- usingSystem.Web.UI.WebControls.WebParts;
- usingSystem.Web.UI.HtmlControls;
- publicpartialclass_Default:System.Web.UI.Page
- {
- protectedvoidPage_Load(objectsender,EventArgse)
- {
- }
- protectedvoidButton1_Click(objectsender,EventArgse)
- {
- stringstringmessage=string.Format("The{0}eventof{1}isfired","Click","Button1");
- this.LabelMessage.Text=message;
- }
- protectedvoidButton2_Click(objectsender,EventArgse)
- {
- stringstringmessage=string.Format("The{0}eventof{1}isfired","Click","Button2");
- this.LabelMessage.Text=message;
- }
- protectedvoidButton3_Click(objectsender,EventArgse)
- {
- stringstringmessage=string.Format("The{0}eventof{1}isfired","Click","Button3");
- this.LabelMessage.Text=message;
- }
- protectedvoidButton_Command(objectsender,CommandEventArgse)
- {
- stringstringmessage=string.Format("The{0}eventof{1}isfired",
"Command",e.CommandArgument);- this.LabelMessage.Text+=";"+message;
- }
- }
以上介紹ASP.NET Postback的Web Page生命周期.
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責任編輯：佚名
來源：
IT168
