ASP.NET Web Forms Web Forms Server Controls Web Forms User Controls
If you have developed a Web Forms page and decide you would like to access its functionality throughout your application, you can make some minor alterations to the file to change it to a user control. Since the <html>, <body>, and <form> elements are not included in user controls, you must include these elements in the containing Web Forms page.
CAUTION: If you are developing a user control in a code-behind class, you must extend the UserControl class rather than the Page class. For more information, see Developing User Controls in a Code-Behind File.
- Remove all <
html>, <body>, and <form> elements from the page. The following example illustrates this conversion.
<html>
<script language="C#" runat=server>
void EnterBtn_Click ( object src, EventArgs e ) {
Label1.Text = "Hi " + Name.Text + " welcome to ASP.NET!";
}
</script>
<body>
<h3> Web Forms Page </h3>
<form>
Enter Name: <asp:textbox id="Name" runat=server/>
<asp:button Text="Enter" OnClick="EnterBtn_Click"
runat=server/>
<br><br>
<asp:label id="Label1" runat=server/>
</form>
</body>
</html>
<html>
<script language="VB" runat=server>
Sub EnterBtn_Click ( Sender as Object, E as EventArgs )
Label1.Text = "Hi " & Name.Text & " welcome to ASP.NET!"
End Sub
</script>
<body>
<h3> Web Forms Page </h3>
<form>
Enter Name: <asp:textbox id="Name" runat=server/>
<asp:button Text="Enter" OnClick="EnterBtn_Click"
runat=server/>
<br><br>
<asp:label id="Label1" runat=server/>
</form>
</body>
</html> |
| |
C# |
VB |
- The user control, following the conversion:
<h3> User Control </h3>
<script language="C#" runat=server>
void EnterBtn_Click ( object src, EventArgs e ) {
Label1.Text = "Hi " + Name.Text + " welcome to ASP.NET!";
}
</script>
Enter Name: <asp:textbox id="Name" runat=server/>
<asp:button Text="Enter" OnClick="EnterBtn_Click"
runat=server/>
<br><br>
<asp:label id="Label1" runat=server/>
<h3> User Control </h3>
<script language="VB" runat=server>
Sub EnterBtn_Click ( Sender as Object, E as EventArgs )
Label1.Text = "Hi " & Name.Text & " welcome to ASP.NET!"
End Sub
</script>
Enter Name: <asp:textbox id="Name" runat=server/>
<asp:button Text="Enter" OnClick="EnterBtn_Click"
runat=server/>
<br><br>
<asp:label id="Label1" runat=server/> |
| |
C# |
VB |
- If there is an @ Page directive in the Web Forms page, change it to an @ Control directive.
NOTE: To avoid parser errors when you convert a page to a user control, remove any attributes supported by the @ Page directive that are not supported by the @ Control directive. For more information, see Directive Syntax.
- Include a className attribute in the @ Control directive. This allows the user control to be strongly typed when it is added to a page or other server controls programmatically.
- Give the control a file name that reflects how you plan to use it and change the file name extension from .aspx to .ascx.
Including a User Control in a Web Forms Page Creating a User Control Defining Web Forms Event-Handling Methods Handling User Control Events