in WPF. How to scroll Objects in ScrollViewer by mouse-dragging, like as iPhone?

user_3073536 0
Viewed 17343

it's done well to scroll by mouse-wheel or scrollbar seed-dragging. but scrolling by mouse-dragging contents on scroll view is not done. How can i implement this action?

        <ScrollViewer x:Name="scrollViewer" Grid.Row="1" HorizontalScrollBarVisibility="Auto" CanContentScroll="True">
            <Grid x:Name="galleryGrid" ShowGridLines="True">
                <Grid.RowDefinitions>
                    <RowDefinition Height="*"></RowDefinition>
                    <RowDefinition Height="*"></RowDefinition>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="500"></ColumnDefinition>
                    <ColumnDefinition Width="500"></ColumnDefinition>
                    <ColumnDefinition Width="500"></ColumnDefinition>
                    <ColumnDefinition Width="500"></ColumnDefinition>
                    <ColumnDefinition Width="500"></ColumnDefinition>
                </Grid.ColumnDefinitions>
                <Button Grid.Column="0" Magin="10,10,10,10">Test</Button>
                <Button Grid.Column="1" Magin="10,10,10,10">Test</Button>
                <Button Grid.Column="2" Magin="10,10,10,10">Test</Button>
                <Button Grid.Column="3" Magin="10,10,10,10">Test</Button>
                <Button Grid.Column="4" Magin="10,10,10,10">Test</Button>
            </Grid>
        </ScrollViewer>
xaml wpf c#
7 Answers

UWP variation:

    Pointer pointer;
    PointerPoint scrollMousePoint ;
    double hOff = 1;

    private void MainScrollviewer_PointerPressed(object sender, Windows.UI.Xaml.Input.PointerRoutedEventArgs e)
    {
        pointer = e.Pointer;
        scrollMousePoint = e.GetCurrentPoint(scrollviewer);
        hOff = scrollviewer.HorizontalOffset;
        scrollviewer.CapturePointer(pointer);
    }

    private void MainScrollviewer_PointerReleased(object sender, Windows.UI.Xaml.Input.PointerRoutedEventArgs e)
    {
        scrollviewer.ReleasePointerCaptures();
    }

    private void MainScrollviewer_PointerMoved(object sender, Windows.UI.Xaml.Input.PointerRoutedEventArgs e)
    {
        if (scrollviewer.PointerCaptures!= null&& scrollviewer.PointerCaptures.Count>0)
        {
          scrollviewer.ChangeView(hOff + (scrollMousePoint.Position.X - e.GetCurrentPoint(scrollviewer).Position.X),null,null);
        }
    }

I know that question was for WPF, but this was best result I found searching for UWP solution.

user_45522070

You can do this in C# WPF like this. note that there are two type of Point classes.From them you should use System.Windows.Point to get this work.These are mouse related events for your ScrollViewer.The code below will scroll your object to both horizontal and vertical inside the ScrollViewer.

   System.Windows.Point ScrollMousePoint1 = new System.Windows.Point();
   double HorizontalOff1 = 1; double VerticalOff1 = 1;
   private void ScrollViewer1_PreviewMouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            ScrollMousePoint1 = e.GetPosition(ScrollViewer1);
            HorizontalOff1 = ScrollViewer1.HorizontalOffset;
            VerticalOff1 = ScrollViewer1.VerticalOffset;
            ScrollViewer1.CaptureMouse();
        }

        private void ScrollViewer1_PreviewMouseMove(object sender, System.Windows.Input.MouseEventArgs e)
        {
            if (ScrollViewer1.IsMouseCaptured)
            {
                ScrollViewer1.ScrollToHorizontalOffset(HorizontalOff1 + (ScrollMousePoint1.X - e.GetPosition(ScrollViewer1).X));
                ScrollViewer1.ScrollToVerticalOffset(VerticalOff1 + (ScrollMousePoint1.Y - e.GetPosition(ScrollViewer1).Y));
            }
        }

        private void ScrollViewer1_PreviewMouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            ScrollViewer1.ReleaseMouseCapture();
        }

        private void ScrollViewer1_PreviewMouseWheel(object sender, System.Windows.Input.MouseWheelEventArgs e)
        {
            ScrollViewer1.ScrollToHorizontalOffset(ScrollViewer1.HorizontalOffset + e.Delta);
            ScrollViewer1.ScrollToVerticalOffset(ScrollViewer1.VerticalOffset + e.Delta);
        }
user_44959000
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