如何：在事件处理程序中查找源元素
本示例演示如何在事件处理程序中查找源元素。
示例
下面的示例演示一个在代码隐藏文件中声明的 Click 事件处理程序。 当用户单击该处理程序所附加到的按钮时，处理程序将更改属性值。 处理程序代码使用在事件参数中报告的路由事件数据的 Source 属性来更改 Source 元素的 Width 属性值。
<Button Click="HandleClick">Button 1</Button>
Private Sub HandleClick(ByVal sender As Object, ByVal e As RoutedEventArgs)
'You must cast the object as a Button element, or at least as FrameworkElement, to set Width
Dim srcButton As Button
srcButton = CType(e.Source, Button)
srcButton.Width = 200
End Sub
void HandleClick(object sender, RoutedEventArgs e)
{
// You must cast the sender object as a Button element, or at least as FrameworkElement, to set Width
Button srcButton = e.Source as Button;
srcButton.Width = 200;
}