/// <summary>
/// Invoked when unhandled MouseWheel event reaches this element. This method is called before the MouseWheel event is fired.
/// </summary>
/// <param name="e">The event arguments for the event.</param>
/// <remarks>This base implementation is empty.</remarks>
protected virtual void OnMouseWheel(MouseWheelEventArgs e)
{ }
protected override void OnMouseWheel(MouseWheelEventArgs e)
{
// migration from OnMouseWheel(int numDetents)
// - no need to check if mouse is over
// - no need to call base class
IScrollViewerFocusSupport svfs = FindScrollControl() as IScrollViewerFocusSupport;
if (svfs == null)
return;
int scrollByLines = SystemInformation.MouseWheelScrollLines; // Use the system setting as default.
IScrollInfo scrollInfo = svfs as IScrollInfo;
if (scrollInfo != null && scrollInfo.NumberOfVisibleLines != 0) // If ScrollControl can shown less items, use this as limit.
scrollByLines = scrollInfo.NumberOfVisibleLines;
int numLines = e.NumDetents * scrollByLines;
if (numLines < 0)
svfs.ScrollDown(-1 * numLines);
else if (numLines > 0)
svfs.ScrollUp(numLines);
}
private static void OnMouseWheelThunk(object sender, MouseWheelEventArgs e)
{
var uiElement = sender as UIElement;
if (uiElement != null)
{
uiElement.OnMouseWheel(e);
}
}
protected override void OnMouseWheel(MouseWheelEventArgs e)
{
// migration from OnMouseWheel(int numDetents)
// - no need to check if mouse is over
// - no need to call base class
int scrollByLines = System.Windows.Forms.SystemInformation.MouseWheelScrollLines; // Use the system setting as default.
int numLines = e.NumDetents * scrollByLines;
if (numLines < 0)
MoveDown(-1 * numLines);
else if (numLines > 0)
MoveUp(numLines);
}