Page 161 - DCAP312_WEB_TECHNOLOGIES_II

Unit 8: Creating More Advanced ASP.NET

8.2.6 How to Create ASP.NET User Controls Notes
You create ASP.NET user controls in much the same way that you design ASP.NET Web pages.
You can use the same HTML elements and controls on a user control that you do on a standard
ASP.NET page. However, the user control does not have html, body, and form elements; and
the file name extension must be .ascx.

To create an ASP.NET user control
• Open the Web site project to which you want to add user controls. If you do not already
have a Website project, you can create one.

• On the Website menu, click Add New Item.
• The Add New Item dialog box appears.
• In the Add New Item dialog box, under Visual Studio installed templates, click Web User
Control.
• In the Name box, type a name for the control.
• By default, the .ascx file name extension is appended to the control name that you type.

• From the Language list, select the programming language that you want to use.
• Optionally, if you want to keep any code for the user control in a separate file, select the
Place code in separate file check box.
• Click Add.

8.2.7 How to Include ASP.NET User Controls in Web Pages
Adding an ASP.NET user control to a Web page is similar to adding other server controls to
the page. However, you must be sure to follow the procedure below so that all of the necessary
elements are added to the page.

To add an ASP.NET user control to a Web page
1. In Visual Web Developer, open the Web page to which you want to add the ASP.NET
user control.

2. Switch to Design view.
3. Select your custom user control file in Solution Explorer, and drag it onto the page.
8.2.8 Creating Reusable Elements with ASP.NET User Controls

ASP.NET user controls let you encapsulate the functionality of multiple server controls in a unit.
User controls are made up of one or more ASP.NET server controls—Button controls, TextBox
controls, and so on—along with any code that is required for the controls to perform the function
that you want to accomplish. The user control can also include custom properties or methods
that reveal the functionality of the user control to a container, which is typically an ASP.NET
page. In this walkthrough, you will create an ASP.NET user control that acts as a picker control.
The picker control has two lists, with a set of choices in one list (the source). Users can select
items in the SourceList list, and then add the items to the Target List.
It has three parts, as follows:

• In the first part, you will create the basic user control, adding controls and code.
• In the second part, you will create a new ASP.NET page (the host page), and then add
the user control to the ASP.NET page.

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