WPF

TCPMem wrote:

I really don't understand why my cursor is far away from the object

Mark Salsbery
Microsoft MVP - Visual C++

TCPMem wrote:

That's exactly what I want. How can I make it?

<Grid x:Name="LayoutRoot" Background="White">
    <Canvas Height="80" HorizontalAlignment="Left" Margin="100,100,0,0" VerticalAlignment="Top" Width="80"
            MouseLeftButtonUp="Canvas_MouseLeftButtonUp"
            MouseMove="Canvas_MouseMove"
            MouseLeftButtonDown="Canvas_MouseLeftButtonDown" >
        <Rectangle Fill="#FF80C1E4" Height="80" Width="80" RenderTransformOrigin="0.5,0.5" />
        <Rectangle Fill="#FF7AB7D8" Height="32" Width="32" Canvas.Left="24" Canvas.Top="24"/>
        <Canvas.RenderTransform>
            <TranslateTransform X="0" Y="0" x:Name="CanvasTransform"/>
        </Canvas.RenderTransform>
    </Canvas>
</Grid>

//protected override void OnMouseMove(MouseEventArgs e)
//{
//    base.OnMouseMove(e);

//    CanvasTransform.X = e.GetPosition(null).X;
//    CanvasTransform.Y = e.GetPosition(null).Y;
//}

Point anchorPoint;
bool isInDrag = false;

private void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    FrameworkElement element = sender as FrameworkElement;
    anchorPoint = e.GetPosition(null);
    element.CaptureMouse();
    isInDrag = true;
}

private void Canvas_MouseMove(object sender, MouseEventArgs e)
{
    if (isInDrag)
    {
        Point currentPoint = e.GetPosition(null);
        CanvasTransform.X = CanvasTransform.X + currentPoint.X - anchorPoint.X;
        CanvasTransform.Y = CanvasTransform.Y + currentPoint.Y - anchorPoint.Y;
        anchorPoint = currentPoint;
    }
}

private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    if (isInDrag)
    {
        FrameworkElement element = sender as FrameworkElement;
        element.ReleaseMouseCapture();
        isInDrag = false;
    }
}

Mark Salsbery
Microsoft MVP - Visual C++

Rectangle item = sender as Rectangle;

FrameworkElement element = sender as FrameworkElement;

John Simmons / outlaw programmer wrote:

I believe you can see if the control "requires scrolling" after setting the content.

John Simmons / outlaw programmer wrote:

You may have to add a handler for the ContentRendered event for the control because the necessary properties may not be set until the content is rendered. I'm not sure about this though.

John Simmons / outlaw programmer wrote:

If you knew the name of the scroller element, you could get it that way. I believe it's "PART_ContentHost".

ScrollViewer sv = (ScrollViewer)richBox.Template.FindName("PART_ContentHost", richBox);

fjparisIII wrote:

Now I have to do two things:

1. See if I can find out from the ScrollViewer whether its content fits within the its vertical height. I'll report my success or failure at this attempt.

private void richTB_MouseEnter(object sender, MouseEventArgs e)
{
    ScrollViewer sv = (ScrollViewer)richTB.Template.FindName("PART_ContentHost", richTB);
    double height = sv.ActualHeight;
    double extentHeight = sv.ExtentHeight;
    double scrollableHeight = sv.ScrollableHeight;
}

fjparisIII wrote:

Fortunately, I think it will be possible for me to use the information on top of the solution to the original problem I had, to make things even better!