Beginning ASP.NET 4.5 in CSharp and VB Opsylum

298 x CHAPTER 8 USER CONTROLS
The cool thing about enums is that you will get IntelliSense in code files, in the Properties Grid,
and even in the code editor for your user controls. Figure 8-6 shows how IntelliSense kicks in for a
VB.NET code file.
FIGURE 8-6
In Figure 8-7 you see the same list with values from the enum in the Properties Grid.
FIGURE 8-7
And in Figure 8-8 you see the same list appear for a property of a user control in Markup View.
FIGURE 8-8
Just as with other code files like classes, you should put your enums in a file under the App_Code
folder. If you have more than one of them, you can store them all in the same file or create a separate
file for each enum.
Enums are great for simple and short lists. They help you find the right item quickly without memorizing
“magic numbers” like 0 or 1, but enable you to use human-readable text strings instead.
In the next exercise, you see how to create an enum and use it in your Banner user control.
TRY IT OUT
Creating Smarter User Controls
In this exercise, you add a second banner to the user control. This banner displays as a horizontal
image inside its own panel. To avoid the two banners showing up at the same time, you add a property
that determines which banner to display. Pages that use the control can then define the correct banner.
1. Start by creating an enumeration that contains two members for the different directions: vertical
and horizontal. To do this, right-click the App_Code folder and choose Add Í Add New Item.
Choose your programming language and add a class file called Direction.