Use the Mouse Wheel action methods that are defined by the IScrollInfo interface : Mouse « Windows Presentation Foundation « VB.Net Tutorial

1. VB.Net Tutorial
2. Windows Presentation Foundation
3. Mouse

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="ScrollViewer_Methods.Window1"
    Title="ScrollViewer IScrollInfo Sample"
    Loaded="onLoad">
<DockPanel>
<TextBlock DockPanel.Dock="Top" FontSize="20" FontWeight="Bold" Margin="10">IScrollInfo Interface Methods</TextBlock>
<StackPanel DockPanel.Dock="Left" Width="150">
    <Button Click="spMouseWheelDown">MouseWheelDown</Button>
    <Button Click="spMouseWheelUp">MouseWheelUp</Button>
    <Button Click="spMouseWheelLeft">MouseWheelLeft</Button>
    <Button Click="spMouseWheelRight">MouseWheelRight</Button>
</StackPanel>  
<Border BorderBrush="Black" Background="White" BorderThickness="2" Width="500" Height="500">
    <ScrollViewer Name="sv1" CanContentScroll="True" VerticalScrollBarVisibility="Visible" HorizontalScrollBarVisibility="Visible">
        <StackPanel Name="sp1">
            <Button>Button 1</Button>
            <Button>Button 5</Button>
            <Rectangle Width="700" Height="500" Fill="Green"/>
            <TextBlock>Rectangle 3</TextBlock>
        </StackPanel> 
    </ScrollViewer>
</Border>
</DockPanel>
</Window>
//File:Window.xaml.vb

Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Controls.Primitives
Imports System.Windows.Documents
Imports System.Windows.Navigation
Imports System.Text

Namespace ScrollViewer_Methods
  Public Partial Class Window1
    Inherits Window
    Private Sub onLoad(sender As Object, e As System.EventArgs)
      DirectCast(sp1, IScrollInfo).CanVerticallyScroll = True
      DirectCast(sp1, IScrollInfo).CanHorizontallyScroll = True
      DirectCast(sp1, IScrollInfo).ScrollOwner = sv1
    End Sub
    Private Sub spMouseWheelDown(sender As Object, e As RoutedEventArgs)
      DirectCast(sp1, IScrollInfo).MouseWheelDown()
    End Sub
    Private Sub spMouseWheelUp(sender As Object, e As RoutedEventArgs)
      DirectCast(sp1, IScrollInfo).MouseWheelUp()
    End Sub
    Private Sub spMouseWheelLeft(sender As Object, e As RoutedEventArgs)
      DirectCast(sp1, IScrollInfo).MouseWheelLeft()
    End Sub
    Private Sub spMouseWheelRight(sender As Object, e As RoutedEventArgs)
      DirectCast(sp1, IScrollInfo).MouseWheelRight()
    End Sub
  End Class
End Namespace

16.91.Mouse
	16.91.1.	MouseDown action on Line
	16.91.2.	Hit Result Behavior
	16.91.3.	Button PreviewMouseLeftButtonDown action and MouseLeftButtonDown action
	16.91.4.	Grid MouseLeftButtonDown action and PreviewMouseLeftButtonDown action
	16.91.5.	Detect whether the mouse button is pressed or released using the MouseButtonState property.
	16.91.6.	Handler MouseLeftButtonDown and MouseLeftButtonUp events
	16.91.7.	Make an object follow the mouse pointer as it moves on the screen.
	16.91.8.	Use Mouse.AddPreviewMouseDownHandler(myEllipse, PreviewMouseDownEllipse);
	16.91.9.	Use Mouse.AddMouseDownHandler(myEllipse, MouseDownEllipse);
	16.91.10.	Use Mouse.PreviewMouseDown /Mouse.MouseDown Attribute from Grid element
	16.91.11.	A line which monitors the mouse entering its area
	16.91.12.	Mouse Position and TranslateTransform
	16.91.13.	Mouse Position
	16.91.14.	Get mouse position with Mouse.GetPosition
	16.91.15.	Replease mouse with Mouse.Capture(null)
	16.91.16.	Retrieving the mouse position relative to controls on a Window
	16.91.17.	Mouse cursor override and clear
	16.91.18.	Check the mouse event source
	16.91.19.	Use the Mouse Wheel action methods that are defined by the IScrollInfo interface
	16.91.20.	Change control background in mouse enter and leave
	16.91.21.	Use EventSetter to add mouse event handler
	16.91.22.	Mouse.LostMouseCaptureEvent
	16.91.23.	Use Mouse.Capture to let a Control capture an event
	16.91.24.	Point Hit Test