Microsoft 9GD00001 manual Coding Event Handlers, 233

Chapter 8: Building Desktop Applications with WPF 233

The previous code shows both the old button1_Click (Button1_Click in VB) event handler and the new NewOrderButton_Click event handler. You might wonder why the button1_Click event handler wasn’t deleted when you deleted it from the Click event in the Properties window, but there’s a good reason for this. What if you had already written code in the event handler? VS leans toward the safe side and does not delete your code. Using the previous steps, you have both event handlers sitting side-by-side, which means that you can easily copy your code from button1_Click into NewOrderButton_Click and then delete the button1_Click event handler. So far, we haven’t written any code for the event handler, which you’ll learn about in the next section.

Coding Event Handlers

One of the tasks you might want to do when a user clicks a button is to open a new window. The first thing you’ll need to do is add a new window. To make this work, you would open Solution Explorer, right-click the project you’re working with, select Add New Item, choose Window (WPF), name the window NewOrder.xaml, and click Add. This will create a new window open in the Designer.

TIP

The project’s Add New Item context menu includes a Window entry, which can save a couple of clicks when creating a new window.

After the Designer loads, you can quickly open the code-behind by pressing F7. In the code-behind, you’ll see the following code:

C#:

public partial class NewOrder : Window

{

public NewOrder()

{

InitializeComponent();

}

}

VB:

Public Class NewOrder

End Class