WPF VB.Net

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="mouseEnterLeave" Height="400" Width="500">
  
                MouseLeave="OnMouseLeaveHandler"
            Name="border1" Margin="10"
            BorderThickness="1"
            BorderBrush="Black"
            VerticalAlignment="Center"
            Width="300" Height="100">
                   HorizontalAlignment="Center">Move Cursor Over Me
    
  


//File:Window.xaml.vb
Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Input
Imports System.Windows.Media
Namespace WpfApplication1
  Public Partial Class Window1
    Inherits Window
    Public Sub New()
      InitializeComponent()
    End Sub
    Private Sub OnMouseEnterHandler(sender As Object, e As MouseEventArgs)
      border1.Background = Brushes.Red
    End Sub
    Private Sub OnMouseLeaveHandler(sender As Object, e As MouseEventArgs)
      border1.Background = Brushes.White
    End Sub
  End Class
End Namespace