ScrollViewer 自动滚动（wpf和Silverlight都可用）

Xaml文件

<ScrollViewer x:Name="AutoScrollViewer" KeyUp="AutoScrollViewer_KeyUp">

</ScrollViewer>

 

c#代码 

使用方法

 

    //Scroll page vertically when focus changes to a control that is outside the viewable area.

private void AutoScrollViewer_KeyUp(object sender, KeyEventArgs e)

{

    if (e.Key == Key.Tab)

    {

        FrameworkElement element = FocusManager.GetFocusedElement() as FrameworkElement;

        if (element != null)

        {

            ScrollViewer scrollViewer = sender as ScrollViewer;

            try

            {

                scrollViewer.ScrollToVerticalOffset(GetVerticalOffset(element, scrollViewer));

            }

            catch

            {

                //if there's an error, don't scroll.

            }

        }

    }

}

 

xaml文件

   <ScrollViewer x:Name="scrollViewer" Grid.Column="1" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Margin="0,5,0,5" MaxHeight="{Binding ActualHeight, RelativeSource={RelativeSource AncestorType={x:Type Border}}}" DockPanel.Dock="Right">

                <ListBox x:Name="lbText" Width="220" l:SelectorExtenders.IsAutoscroll="True"   Height="Auto"  SelectionMode="Single"  Margin="0,0,5,0"  RequestBringIntoView="lbText_RequestBringIntoView" SelectionChanged="lbText_SelectionChanged">

                    <ListBox.ItemTemplate>

                        <DataTemplate>

                            <StackPanel x:Name="spText" MouseLeftButtonUp="StackPanel_MouseLeftButtonUp" Margin="0,6,5,2" Cursor="Hand">

                            <TextBlock x:Name="tbEn" TextWrapping="Wrap" Text="{Binding En}"  Width="200" Margin="0,0,5,0"/>

                            <TextBlock x:Name="tbCh" TextWrapping="Wrap" Text="{Binding Ch}"  Width="200" Margin="0,0,5,0"/>

                            </StackPanel>

                        </DataTemplate>

                    </ListBox.ItemTemplate>

                </ListBox>

            </ScrollViewer>

 

在listbox中使用例子

ListBoxItem myListBoxItem =

 (ListBoxItem)(lbText.ItemContainerGenerator.ContainerFromItem(lbText.Items[i]));

                 FrameworkElement element = myListBoxItem as FrameworkElement;

                 scrollViewer.ScrollToVerticalOffset(GetVerticalOffset(element, scrollViewer));

 

 

公用function方法：

 

private double GetVerticalOffset(FrameworkElement child, ScrollViewer scrollViewer)

{

    // Ensure the control is scrolled into view in the ScrollViewer. 

    GeneralTransform focusedVisualTransform = child.TransformToVisual(scrollViewer);

    Point topLeft = focusedVisualTransform.Transform(new Point(child.Margin.Left, child.Margin.Top));

    Rect rectangle = new Rect(topLeft, child.RenderSize);

    //If the control is taller than the viewport, don't scroll down further than the top of the control. 

    double controlRectangleBottom = rectangle.Bottom - scrollViewer.ViewportHeight > scrollViewer.ViewportHeight ? scrollViewer.ViewportHeight : rectangle.Bottom;

    double newOffset = scrollViewer.VerticalOffset + (controlRectangleBottom - scrollViewer.ViewportHeight);

    return newOffset < 0 ? 0 : newOffset; // no use returning negative offset

}

 

在wpf和Silverlight中都可以用