/// <summary>
/// Starts the dragging operation.
/// </summary>
/// <param name="uiElt">The dragged UI element.</param>
private static void DragStarted(UIElement uiElt)
{
isMouseDown = false;
Mouse.Capture(uiElt);
// Daten des Drag-Elements holen
var data = CurrentDragSourceAdvisor.GetDataObject(draggedElt);
// und diese Daten mit Zusatzinformationen anreichern
data.SetData(DragOffsetFormat, offsetPoint);
data.SetData(DragSourceFormat, draggedElt);
// Die unterstützten DnD-Effekte bei der Drag-Quelle erfragen
var supportedEffects = CurrentDragSourceAdvisor.SupportedEffects;
// Perform Drag and Drop operation
var effects = System.Windows.DragDrop.DoDragDrop(draggedElt, data, supportedEffects);
// finish DnD operation
CurrentDragSourceAdvisor.FinishDrag(draggedElt, effects);
// Clean up
RemovePreviewAdorner();
Mouse.Capture(null);
draggedElt = null;
}
private static void DragSource_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (_isMouseDown && IsDragGesture(e.GetPosition(CurrentDragSourceAdvisor.GetTopContainer())))
{
DragStarted(sender as UIElement);
}
}
private static void DragStarted(UIElement uiElt)
{
_isMouseDown = false;
if (uiElt == null || _draggedElt == null)
{
return;
}
//Mouse.Capture(uiElt);
DataObject data = CurrentDragSourceAdvisor.GetDataObject(_draggedElt);
data.SetData(DragOffsetFormat, _offsetPoint);
DragDropEffects supportedEffects = CurrentDragSourceAdvisor.SupportedEffects;
// Perform DragDrop
DragDropEffects effects = DragDrop.DoDragDrop(_draggedElt, data, supportedEffects);
CurrentDragSourceAdvisor.FinishDrag(_draggedElt, effects);
// Clean up
RemovePreviewAdorner();
//Mouse.Capture(null);
_draggedElt = null;
}
private static void DragSource_PreviewMouseUp(object sender, MouseButtonEventArgs e)
{
if (_isMouseDown && IsDragGesture(e.GetPosition(CurrentDragSourceAdvisor.GetSourceTopContainer())))
{
_isMouseDown = false;
Mouse.Capture(null);
}
}
private static void DragSource_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (CurrentDragSourceAdvisor != null && e.LeftButton == MouseButtonState.Pressed &&
IsDragGesture(e.GetPosition(CurrentDragSourceAdvisor.GetTopContainer())))
{
DragStarted(sender as UIElement);
}
else
{
Mouse.Capture(null);
}
}
/* ____________________________________________________________________
* Drag Source events
* ____________________________________________________________________
*/
private static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Make this the new drag source
CurrentDragSourceAdvisor = GetDragSourceAdvisor(sender as DependencyObject);
if (CurrentDragSourceAdvisor.IsDraggable(e.Source as UIElement) == false)
{
return;
}
_draggedElt = e.Source as UIElement;
_dragStartPoint = e.GetPosition(CurrentDragSourceAdvisor.GetTopContainer());
_offsetPoint = e.GetPosition(_draggedElt);
_isMouseDown = true;
}
private static void DragStarted(UIElement uiElt)
{
_isMouseDown = false;
Mouse.Capture(uiElt);
DataObject data = CurrentDragSourceAdvisor.GetDataObject(_draggedElt, _dragStartPoint);
// NOTE: observed as being null during testing
if (data != null)
{
data.SetData(DragOffsetFormat, _offsetPoint);
DragDropEffects supportedEffects = CurrentDragSourceAdvisor.SupportedEffects;
// Perform DragDrop
DragDropEffects effects = System.Windows.DragDrop.DoDragDrop(_draggedElt, data, supportedEffects);
CurrentDragSourceAdvisor.FinishDrag(_draggedElt, _dragStartPoint, effects);
}
// Clean up
RemovePreviewAdorner();
Mouse.Capture(null);
_draggedElt = null;
}
