在ASP.NET2.0里，Page指令的一个显著的变化就是从CodeBehind改变成了CodeFile，下面是一个较为典型的例子
<%@ Page Language="C#" CodeFile="MyPage.aspx.cs"
Inherits="PS.AspDotNet20.MyPage" %>
<html xmlns="http://www.w3.org/1999/xhtml" >
<body>
<form id="form1" runat="server">
Enter your name: <asp:TextBox ID="nameTextBox" runat="server" /><br />
<asp:Button ID="enterButton" runat="server"
Text="Enter" OnClick="enterButton_Click" />
<br />
<asp:Label ID="messageLabel" runat="server" />
</form>
</body>
</html>
我们很容易写出他的后台代码MyPage.aspx.cs：
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace PS.AspDotNet20
{
public partial class MyPage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{ }
protected void enterButton_Click(object sender, EventArgs e)
{
messageLabel.Text = "Hello " + nameTextBox.Text + "!";
}
}
}
现在在ASP.NET2.0里，当用户请求MyPage.aspx时，它将生成两个类文件：
一个是由后台文件MyPage.aspx.cs里定义的类生成
一个是由MyPage.aspx生成的类。
这两个类文件都是不完全类型（partial），
毫无疑问，在ASP.NET框架处理页面前，最终必须建立一个完整的类，类似如下
namespace PS.AspDotNet20
{
public partial class MyPage : IRequiresSessionState
{
protected global::System.Web.UI.WebControls.TextBox nameTextBox;
protected global::System.Web.UI.WebControls.Button enterButton;
protected global::System.Web.UI.WebControls.Label messageLabel;
protected global::System.Web.UI.HtmlControls.HtmlForm form1;
protected System.Web.Profile.DefaultProfile Profile
{
get
{
return ((System.Web.Profile.DefaultProfile)(this.Context.Profile));
}
}
protected System.Web.HttpApplication ApplicationInstance
{
get
{
return ((System.Web.HttpApplication)(this.Context.ApplicationInstance));
}
}
}
}
这样您就可以看到，这里的原理和ASP.NET1.X类似了，所有的控件都以类成员的省份显示。当然上面这种“整合”是系统自动运行的，所以从本质上看，ASP.NET2.0解析*.aspx里面的控件并生成类成员和ASP.NET1.X类似的。
另外，这种类的放置位置和ASP.NET1.X非常类型，默认放置在临时文件，当然如果您不知道临时文件夹
的具体内容，可以参考如下一篇文章。
http://www.microsoft.com/china/MSDN/library/archives/library/DNAspp/html/dngrftheaspnethttpruntime.asp
这样.ASPX生成的编译代码类似如下：
namespace ASP
{
public class MyPage_aspx : global::PS.AspDotNet20.MyPage
{
private static bool @__initialized = false;
private static object @__fileDependencies;
public MyPage_aspx()
{
string[] dependencies;
AppRelativeVirtualPath = "~/MyPage.aspx";
if ((global::ASP.MyPage_aspx.@__initialized == false))
{
dependencies = new string[2];
dependencies[0] = "~/MyPage.aspx";
dependencies[1] = "~/MyPage.aspx.cs";
global::ASP.MyPage_aspx.@__fileDependencies = this.GetWrappedFileDependencies(dependencies);
global::ASP.MyPage_aspx.@__initialized = true;
}
this.Server.ScriptTimeout = 30000000;
}
private global::System.Web.UI.WebControls.TextBox @__BuildControlnameTextBox()
{
global::System.Web.UI.WebControls.TextBox @__ctrl;
@__ctrl = new global::System.Web.UI.WebControls.TextBox();
this.nameTextBox = @__ctrl;
@__ctrl.ApplyStyleSheetSkin(this);
@__ctrl.ID = "nameTextBox";
return @__ctrl;
}
private global::System.Web.UI.WebControls.Button @__BuildControlenterButton()
{
global::System.Web.UI.WebControls.Button @__ctrl;
@__ctrl = new global::System.Web.UI.WebControls.Button();
this.enterButton = @__ctrl;
@__ctrl.ApplyStyleSheetSkin(this);
@__ctrl.ID = "enterButton";
@__ctrl.Text = "Enter";
@__ctrl.Click += new System.EventHandler(this.enterButton_Click);
return @__ctrl;
}
private global::System.Web.UI.WebControls.Label @__BuildControlmessageLabel()
{
global::System.Web.UI.WebControls.Label @__ctrl;
@__ctrl = new global::System.Web.UI.WebControls.Label();
this.messageLabel = @__ctrl;
@__ctrl.ApplyStyleSheetSkin(this);
@__ctrl.ID = "messageLabel";
return @__ctrl;
}
private global::System.Web.UI.HtmlControls.HtmlForm @__BuildControlform1()
{
global::System.Web.UI.HtmlControls.HtmlForm @__ctrl;
@__ctrl = new global::System.Web.UI.HtmlControls.HtmlForm();
this.form1 = @__ctrl;
@__ctrl.ID = "form1";
System.Web.UI.IParserAccessor @__parser = ((System.Web.UI.IParserAccessor)(@__ctrl));
@__parser.AddParsedSubObject(new System.Web.UI.LiteralControl("\r\n Enter your name: "));
global::System.Web.UI.WebControls.TextBox @__ctrl1;
@__ctrl1 = this.@__BuildControlnameTextBox();
@__parser.AddParsedSubObject(@__ctrl1);
@__parser.AddParsedSubObject(new System.Web.UI.LiteralControl("<br />\r\n "));
global::System.Web.UI.WebControls.Button @__ctrl2;
@__ctrl2 = this.@__BuildControlenterButton();
@__parser.AddParsedSubObject(@__ctrl2);
@__parser.AddParsedSubObject(new System.Web.UI.LiteralControl("\r\n <br />\r\n "));
global::System.Web.UI.WebControls.Label @__ctrl3;
@__ctrl3 = this.@__BuildControlmessageLabel();
@__parser.AddParsedSubObject(@__ctrl3);
@__parser.AddParsedSubObject(new System.Web.UI.LiteralControl("\r\n "));
return @__ctrl;
}
private void @__BuildControlTree(MyPage_aspx @__ctrl)
{
System.Web.UI.IParserAccessor @__parser = ((System.Web.UI.IParserAccessor)(@__ctrl));
@__parser.AddParsedSubObject(new System.Web.UI.LiteralControl(
"\r\n\r\n<html xmlns=\"http://www.w3.org/1999/xhtml\" >\r\n<body>\r\n "));
global::System.Web.UI.HtmlControls.HtmlForm @__ctrl1;
@__ctrl1 = this.@__BuildControlform1();
@__parser.AddParsedSubObject(@__ctrl1);
@__parser.AddParsedSubObject(new System.Web.UI.LiteralControl("\r\n</body>\r\n</html>\r\n"));
}
protected override void FrameworkInitialize()
{
base.FrameworkInitialize();
this.@__BuildControlTree(this);
this.AddWrappedFileDependencies(global::ASP.MyPage_aspx.@__fileDependencies);
this.Request.ValidateInput();
}
public override int GetTypeHashCode()
{
return -731145279;
}
}
}
上面说过，在ASP.NET框架处理页面前，最终必须建立一个完整的类，这种后果是页面在运行时编译，结果影响了性能，可以使用aspnet_compiler.exe 编译，（aspnet_compiler.exe 是.NET2.0新增的），以后回介绍这个命令。