ScrollChangedEventArgs Class (System.Windows.Controls)

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.NET Framework Class Library
ScrollChangedEventArgs Class

Describes a change in the scrolling state and contains the required arguments for a ScrollChanged event.

Inheritance Hierarchy
System.Object
  System.EventArgs
    System.Windows.RoutedEventArgs
      System.Windows.Controls.ScrollChangedEventArgs

Namespace:  System.Windows.Controls
Assembly:  PresentationFramework (in PresentationFramework.dll)
Syntax
Visual Basic
Public Class ScrollChangedEventArgs _
	Inherits RoutedEventArgs
C#
public class ScrollChangedEventArgs : RoutedEventArgs
Visual C++
public ref class ScrollChangedEventArgs : public RoutedEventArgs
F#
type ScrollChangedEventArgs =  
    class
        inherit RoutedEventArgs
    end

The ScrollChangedEventArgs type exposes the following members.

Properties
  Name Description
Public property ExtentHeight Gets the updated height of the ScrollViewer extent.
Public property ExtentHeightChange Gets a value that indicates the change in height of the ScrollViewer extent.
Public property ExtentWidth Gets the updated width of the ScrollViewer extent.
Public property ExtentWidthChange Gets a value that indicates the change in width of the ScrollViewer extent.
Public property Handled Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. (Inherited from RoutedEventArgs.)
Public property HorizontalChange Gets a value that indicates the change in horizontal offset for a ScrollViewer.
Public property HorizontalOffset Gets the updated horizontal offset value for a ScrollViewer.
Public property OriginalSource Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. (Inherited from RoutedEventArgs.)
Public property RoutedEvent Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. (Inherited from RoutedEventArgs.)
Public property Source Gets or sets a reference to the object that raised the event. (Inherited from RoutedEventArgs.)
Public property VerticalChange Gets a value that indicates the change in vertical offset of a ScrollViewer.
Public property VerticalOffset Gets the updated value of the vertical offset for a ScrollViewer.
Public property ViewportHeight Gets the updated value of the viewport height for a ScrollViewer.
Public property ViewportHeightChange Gets a value that indicates the change in value of the viewport height for a ScrollViewer.
Public property ViewportWidth Gets the updated value of the viewport width for a ScrollViewer.
Public property ViewportWidthChange Gets a value that indicates the change in viewport width of a ScrollViewer.
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Methods
  Name Description
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Protected method InvokeEventHandler Performs proper type casting before invoking the type-safe ScrollChangedEventHandler delegate (Overrides RoutedEventArgs.InvokeEventHandler(Delegate, Object).)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method OnSetSource When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. (Inherited from RoutedEventArgs.)
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
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Examples

This example shows how to handle the ScrollChanged event of a ScrollViewer.

A FlowDocument element with Paragraph parts is defined in XAML. When the ScrollChanged event occurs due to user interaction, a handler is invoked, and text is written to a TextBlock indicating that the event has occurred.

XAML

<ScrollViewer Name="sv1" CanContentScroll="False" ScrollChanged="sChanged">

  <FlowDocument FontFamily="Arial" PageWidth="400">
    <Paragraph>
      Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut
      laoreet dolore magna aliquam erat volutpat.  Ut wisi enim ad minim veniam, quis nostrud exerci tation
      ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure.
      Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut
      laoreet dolore magna aliquam erat volutpat.  Ut wisi enim ad minim veniam, quis nostrud exerci tation
      ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure.
      Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut
      laoreet dolore magna aliquam erat volutpat.  Ut wisi enim ad minim veniam, quis nostrud exerci tation
      ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure.
    </Paragraph>


...


    <Paragraph>
      Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut
      laoreet dolore magna aliquam erat volutpat.  Ut wisi enim ad minim veniam, quis nostrud exerci tation
      ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure.
      Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut
      laoreet dolore magna aliquam erat volutpat.  Ut wisi enim ad minim veniam, quis nostrud exerci tation
      ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure.
      Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut
      laoreet dolore magna aliquam erat volutpat.  Ut wisi enim ad minim veniam, quis nostrud exerci tation
      ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure.
    </Paragraph>

  </FlowDocument>
</ScrollViewer>
Visual Basic

Private Sub sChanged(ByVal sender As Object, ByVal args As ScrollChangedEventArgs)


    If (sv1.CanContentScroll = True) Then
        tBlock1.Foreground = System.Windows.Media.Brushes.Red
        tBlock1.Text = "ScrollChangedEvent just Occurred"
        tBlock3.Text = "ExtentWidth is now " + args.ExtentWidth.ToString()
        tBlock4.Text = "ExtentHeightChange was " + args.ExtentHeightChange.ToString()
        tBlock5.Text = "ExtentWidthChange was " + args.ExtentWidthChange.ToString()
        tBlock6.Text = "HorizontalOffset is now " + args.HorizontalOffset.ToString()
        tBlock7.Text = "VerticalOffset is now " + args.VerticalOffset.ToString()
        tBlock8.Text = "HorizontalChange was " + args.HorizontalChange.ToString()
        tBlock9.Text = "VerticalChange was " + args.VerticalChange.ToString()
        tBlock10.Text = "ViewportHeight is now " + args.ViewportHeight.ToString()
        tBlock11.Text = "ViewportWidth is now " + args.ViewportWidth.ToString()
        tBlock12.Text = "ViewportHeightChange was " + args.ViewportHeightChange.ToString()
        tBlock13.Text = "ViewportWidthChange was " + args.ViewportWidthChange.ToString()

    Else
        tBlock1.Text = ""

    End If
C#

private void sChanged(object sender, ScrollChangedEventArgs e)
{
    if (sv1.CanContentScroll == true)
    {
        tBlock1.Foreground = System.Windows.Media.Brushes.Red;
        tBlock1.Text = "ScrollChangedEvent just Occurred";
        tBlock2.Text = "ExtentHeight is now " + e.ExtentHeight.ToString();
        tBlock3.Text = "ExtentWidth is now " + e.ExtentWidth.ToString();
        tBlock4.Text = "ExtentHeightChange was " + e.ExtentHeightChange.ToString();
        tBlock5.Text = "ExtentWidthChange was " + e.ExtentWidthChange.ToString();
        tBlock6.Text = "HorizontalOffset is now " + e.HorizontalOffset.ToString();
        tBlock7.Text = "VerticalOffset is now " + e.VerticalOffset.ToString();
        tBlock8.Text = "HorizontalChange was " + e.HorizontalChange.ToString();
        tBlock9.Text = "VerticalChange was " + e.VerticalChange.ToString();
        tBlock10.Text = "ViewportHeight is now " + e.ViewportHeight.ToString();
        tBlock11.Text = "ViewportWidth is now " + e.ViewportWidth.ToString();
        tBlock12.Text = "ViewportHeightChange was " + e.ViewportHeightChange.ToString();
        tBlock13.Text = "ViewportWidthChange was " + e.ViewportWidthChange.ToString();
    }
    else
    {
        tBlock1.Text = "";
    }
Version Information

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also

Reference

System.Windows.Controls Namespace
ScrollChanged
ScrollViewer

Other Resources

ScrollViewer Overview