scrollviewer current position

Question

Hi,

I am using scrollviwer. inside it i place a stackpanel and some controls are added to this stackpanel from codebehind. so after adding all the contents, when i checked in code, i found the actual height of stackpanel is 1200. so the scrolling height of scrollviwer will be 1200? so when i start the scrolling, i need to find the current position of scrollviewer. Say the value is 300 at some point, 700 at some other point and 1200 and the end of scrolling ( to the bottom of page). how can i check this in code? will it affect the maximise/minimise state of window?

Answer 1

Hiya, there are a load of special properties in there, for you to determine and move the scrollviewer from code.

Check out the following:

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.extentheight.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.extentwidth.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.scrollablewidth.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.scrollableheight.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.panningratio.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.contenthorizontaloffset.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.horizontaloffset.aspx

http://msdn.microsoft.com/en-us/library/system.windows.controls.scrollviewer.verticaloffset

I show an examination of the ScrollViewer and detecting/calculating/manipulating some of these properties in the following TechNet sample:

http://code.msdn.microsoft.com/SubtleScrollViewer-No-d31d3248

 

That should get you started, or at l;east give you the terms to search better with :)

Regards,
Pete

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#PEJL

Answer 2

Try this link:

http://social.msdn.microsoft.com/Forums/en/wpf/thread/bdf2f91e-469a-4931-b5aa-35c5ce58591f

http://www.codeproject.com/Articles/39244/Scroll-Synchronization

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Sivalingam

Answer 3

ScrollViewer Height and Width is affected by window resizing.

To get the values related to scrollviewer Position you can use ScrollViewer_ScrollChanged Event. The event is triggered whenever you scroll the ScrollViewer.

Here is a code snippet!!!

private void ScrollViewer_ScrollChanged(object sender, ScrollChangedEventArgs e)
        {
            Console.WriteLine("Horizontal Position: " + e.HorizontalOffset); /* Gets the current Horizontal Position of the scrollviewer*/
            Console.WriteLine("Change in Horizontal Position: " + e.HorizontalChange); /* Gets the change in Horizontal Position */
            Console.WriteLine("Vertical Position: " + e.VerticalOffset); /* Gets the current Vertical Position of the scrollviewer*/
            Console.WriteLine("Change in Vertical Position : " + e.VerticalChange); /* Gets the change in Vertical Position */
            Console.WriteLine("Height of the ScrollViewer : " + e.ViewportHeight); /*Gets the Total Height of the ScrollViewer*/
            Console.WriteLine("Width of the ScrollViewer: " + e.ViewportWidth); /*Gets the Total Width of the ScrollViewer*/
        }

Output of the Code:

Horizontal Position: 0

Change in Horizontal Position: 0

Vertical Position: 145.650541516245

Change in Vertical Position : 9.24765342960288

Height of the ScrollViewer: 311

Width of the ScrollViewer: 492

Happy Programming!!!

Answer 4

Hello Ajin.

If your ScrollViewer had a set height of 100 and the content had a height of 1200, your ScrollableHeight would be 1100.  (Content Height less ScrollViewer ActualHeight)

Knowing that you could always just bind to the ScrollViewer.ContentVerticalOffset or call it from code-behind.

private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
{
	double a = scrollViewer.ContentVerticalOffset;
	MessageBox.Show(a.ToString());
}

And the binding in XAML...

<Grid x:Name="LayoutRoot">
		<ScrollViewer x:Name="scrollViewer" HorizontalAlignment="Left" Height="100" VerticalAlignment="Top" Width="100">
			<StackPanel Height="1200" Width="100">
				<StackPanel.Background>
					<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
						<GradientStop Color="Black" Offset="0"/>
						<GradientStop Color="White" Offset="0.9"/>
						<GradientStop Color="Red" Offset="1"/>
					</LinearGradientBrush>
				</StackPanel.Background>
			</StackPanel>
		</ScrollViewer>
		<TextBlock HorizontalAlignment="Left" TextWrapping="Wrap" Text="{Binding ScrollableHeight, ElementName=scrollViewer}" VerticalAlignment="Top" Margin="104,0,0,0"/>
		<TextBlock HorizontalAlignment="Left" TextWrapping="Wrap" Text="{Binding ContentVerticalOffset, ElementName=scrollViewer, Mode=OneWay}" VerticalAlignment="Top" Margin="104,19.96,0,0"/>
		<Button Content="Button" HorizontalAlignment="Left" VerticalAlignment="Top" Width="75" Margin="104,78.04,0,0" Click="Button_Click"/>
	</Grid>

~Christine

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My Gallery

Answer 5

hi i am unable to get scroll_Changed Event in SilverLight please suggest me..