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Hoe te handelen: de ScrollChanged-gebeurtenis afhandelen

Voorbeeld

In dit voorbeeld ziet u hoe de gebeurtenis ScrollChanged van een ScrollViewerkan worden afgehandeld.

Een FlowDocument element met Paragraph onderdelen wordt gedefinieerd in XAML. Wanneer de ScrollChanged gebeurtenis optreedt vanwege gebruikersinteractie, wordt een handler aangeroepen en wordt tekst naar een TextBlock geschreven die aangeeft dat de gebeurtenis heeft plaatsgevonden.

<ScrollViewer Name="svrContent" 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>

private void sChanged(object sender, ScrollChangedEventArgs e)
{
    if (svrContent.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 = "";
    }

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

Zie ook

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