This article provides a brief overview of the code-behind
model, which is introduced in ASP.NET.
ASP.NET supports two methods to author pages:
In-Line Code
In-line code is code that is embedded directly within the ASP.NET
page. The following code represents
a sample ASP.NET page that includes in-line code:
Myinlinecode.aspx
<%@ Language=C# %>
<HTML>
<script runat="server" language="C#">
void MyButton_OnClick(Object sender, EventArgs e)
{
MyLabel.Text = MyTextbox.Text.ToString();
}
</script>
<body>
<form id="MyForm" runat="server">
<asp:textbox id="MyTextbox" text="Hello World" runat="server"></asp:textbox>
<asp:button id="MyButton" text="Echo Input" OnClick="MyButton_OnClick" runat="server"></asp:button>
<asp:label id="MyLabel" runat="server"></asp:label>
</form>
</body>
</HTML>
Code-Behind
Code-behind refers to code for
your ASP.NET page that is contained within a separate class file. This allows a
clean separation of your HTML from your presentation logic. The following
sample illustrates an ASP.NET code-behind page:
MyCodebehind.aspx
<%@ Language="C#" Inherits="MyStuff.MyClass" %>
<HTML>
<body>
<form id="MyForm" runat="server">
<asp:textbox id="MyTextBox" text="Hello World" runat="server"></asp:textbox>
<asp:button id="MyButton" text="Echo Input" Onclick="MyButton_Click" runat="server"></asp:button>
<asp:label id="MyLabel" runat="server" />
</form>
</body>
</HTML>
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace MyStuff
{
public class MyClass : Page
{
protected System.Web.UI.WebControls.Label MyLabel;
protected System.Web.UI.WebControls.Button MyButton;
protected System.Web.UI.WebControls.TextBox MyTextBox;
public void MyButton_Click(Object sender, EventArgs e)
{
MyLabel.Text = MyTextBox.Text.ToString();
}
}
}
In the preceding sample, you can use the following syntax to compile
Mycodebehind.cs:
csc.exe /out:mycodebehind.dll /t:library mycodebehind.cs
When you use the following code, the code-behind page
inherits from the
Page class. The
Page class resides in the
System.Web.UI namespace:
public class MyClass : Page
Inheriting from the
Page class gives the code-behind page access to the ASP.NET intrinsic
objects, such as
Request and
Response. In addition, inheriting from the
Page class provides a framework for handling events for controls
within the ASP.NET page.
In the preceding sample, the code-behind page is compiled before
ASP.NET runs. Alternatively, you can reference the code-behind class by using
an SRC tag as follows:
<%@ Language="C#" Inherits="MyStuff.MyClass" src="MyCodebehind.cs" %>
In this case, ASP.NET compiles the code-behind page on the fly. Notice
that this compilation step only occurs when the code-behind file is updated
(which is detected through a timestamp change).
Code-Behind Support in Visual Studio .NET
When you use Microsoft Visual Studio .NET to create ASP.NET Web Forms,
code-behind pages are the default method. In addition, Visual Studio .NET
automatically performs precompilation for you when you build your solution.
Note that code-behind pages that are created in Visual Studio .NET include a
special page attribute,
Codebehind, which Visual Studio .NET uses.
For
additional information%1, click the article number%2 below to view the
article%2 in the Microsoft Knowledge Base:
313105Â
(http://kbalertz.com/Feedback.aspx?kbNumber=313105/EN-US/
)
BUG: Cannot Compile Code-Behind Files That Use Src Attribute on a UNC Share