public DragDropEffects DoDragDrop(UIElement aSourceElement, IDataObject aDataObject, DragDropEffects aEffects, FrameworkElement aSourceVisual)
{
QueryContinueDragEventHandler queryContinue = null;
DragDropEffects resultEffects = DragDropEffects.None;
if (aDataObject != null && aSourceElement != null)
{
DragDrop.AddPreviewQueryContinueDragHandler(aSourceElement, queryContinue = new QueryContinueDragEventHandler(DragHelper_OnQueryContinueDrag));
IsDragging = true;
CreateDragDropWindow(aSourceVisual);
this.iDragdropWindow.Show();
try
{
resultEffects = DragDrop.DoDragDrop(aSourceElement, aDataObject, aEffects);
}
catch (Exception ex)
{
Linn.UserLog.WriteLine("Exception caught performing DragDrop : " + ex.ToString());
}
DestroyDragDropWindow();
DragDrop.RemovePreviewQueryContinueDragHandler(aSourceElement, DragHelper_OnQueryContinueDrag);
IsDragging = false;
System.Windows.Input.Mouse.Capture(null);
DestroyDragDropWindow();
}
return(resultEffects);
}
/// <summary>
/// Initializes a new instance of the <see cref="DragAdorner{T}"/> class.
/// </summary>
/// <param name="adornedElement">The drag source.</param>
/// <param name="child">The content to render.</param>
protected DragAdorner(UIElement adornedElement, T child)
: base(adornedElement)
{
this.elementOffset = adornedElement.PointToScreen(new Point(0, 0)) - User32.GetMousePosition();
var mp = User32.GetMousePosition(adornedElement) + this.elementOffset;
this.Offset = new TranslateTransform(mp.X, mp.Y);
child.RenderTransform = this.Offset;
base.Child = child;
DragDrop.AddPreviewQueryContinueDragHandler(adornedElement, this.UpdatePosition);
}
private void StartDrag(MouseEventArgs args)
{
IDataObject data = null;
UIElement dragelement = null;
// ADD THE DATA
if (this.Callback != null)
{
DragDataWrapper dw = new DragDataWrapper();
data = new DataObject(typeof(DragDataWrapper).ToString(), dw);
if ((this.Callback.SupportedActions & DragDropProviderActions.MultiFormatData) != 0)
{
this.Callback.AppendData(ref data, args);
}
if ((this.Callback.SupportedActions & DragDropProviderActions.Data) != 0)
{
dw.Data = this.Callback.GetData();
}
if ((this.Callback.SupportedActions & DragDropProviderActions.Visual) != 0)
{
dragelement = this.Callback.GetVisual(args);
}
else
{
dragelement = args.OriginalSource as UIElement;
}
dw.Source = this.DragSource;
dw.Shim = this.Callback;
Debug.Assert(this.DragScope == null, "The DragDataWrapper is meant for in-proc... Sorry for asserting, just wanted to confirm.. comment out assertion if needed");
}
else
{
dragelement = args.OriginalSource as UIElement;
data = new DataObject(typeof(UIElement).ToString(), dragelement);
}
if (dragelement == null || data == null || dragelement == this.DragSource)
{
return;
}
DragEventHandler dragOver = null;
DragEventHandler dragLeave = null;
QueryContinueDragEventHandler queryContinue = null;
GiveFeedbackEventHandler giveFeedback = null;
DragDropEffects effects = this.GetDragDropEffects();
DragDropEffects resultEffects;
// Inprocess Drag ...
if (this.DragScope != null)
{
bool previousAllowDrop = this.DragScope.AllowDrop;
this.adorner = new DragAdorner(this.DragScope, (UIElement)dragelement, true, this.Opacity);
this.layer = AdornerLayer.GetAdornerLayer(this.DragScope as Visual);
this.layer.Add(this.adorner);
if (this.DragScope != this.DragSource)
{
this.DragScope.AllowDrop = true;
DragDrop.AddPreviewDragOverHandler((DependencyObject)this.DragScope, dragOver = new DragEventHandler(DragScope_DragOver));
DragDrop.AddPreviewDragLeaveHandler(this.DragScope, dragLeave = new DragEventHandler(DragScope_DragLeave));
DragDrop.AddPreviewQueryContinueDragHandler(this.DragSource, queryContinue = new QueryContinueDragEventHandler(OnQueryContinueDrag));
}
try
{
this.IsDragging = true;
this.mouseLeftScope = false;
resultEffects = DragDrop.DoDragDrop(this.DragSource, data, effects);
this.DragFinished(resultEffects);
}
catch
{
Debug.Assert(false);
}
if (this.DragScope != this.DragSource)
{
this.DragScope.AllowDrop = previousAllowDrop;
DragDrop.RemovePreviewDragOverHandler(this.DragScope, dragOver);
DragDrop.RemovePreviewDragLeaveHandler(this.DragScope, dragLeave);
DragDrop.RemovePreviewQueryContinueDragHandler(this.DragSource, queryContinue);
}
}
else
{
DragDrop.AddPreviewQueryContinueDragHandler(this.DragSource, queryContinue = new QueryContinueDragEventHandler(OnQueryContinueDrag));
DragDrop.AddGiveFeedbackHandler(this.DragSource, giveFeedback = new GiveFeedbackEventHandler(OnGiveFeedback));
this.IsDragging = true;
if ((this.Callback.SupportedActions & DragDropProviderActions.Visual) != 0)
{
this.CreateDragDropWindow(dragelement);
this.dragdropWindow.Show();
}
try
{
resultEffects = DragDrop.DoDragDrop(this.DragSource, data, effects);
}
finally
{
}
if ((this.Callback.SupportedActions & DragDropProviderActions.Visual) != 0)
{
this.DestroyDragDropWindow();
}
DragDrop.RemovePreviewQueryContinueDragHandler(this.DragSource, OnQueryContinueDrag);
DragDrop.AddGiveFeedbackHandler(this.DragSource, OnGiveFeedback);
this.IsDragging = false;
this.DragFinished(resultEffects);
}
}
void StartDrag(MouseEventArgs args)
{
IDataObject data = null;
UIElement dragelement = null;
// ADD THE DATA
if (_callback != null)
{
DragDataWrapper dw = new DragDataWrapper();
data = new DataObject(typeof(DragDataWrapper).ToString(), dw);
if ((_callback.SupportedActions & DragDropProviderActions.MultiFormatData) != 0)
{
_callback.AppendData(ref data, args);
}
if ((_callback.SupportedActions & DragDropProviderActions.Data) != 0)
{
dw.Data = _callback.GetData();
}
if ((_callback.SupportedActions & DragDropProviderActions.Visual) != 0)
{
dragelement = _callback.GetVisual(args);
}
else
{
dragelement = args.OriginalSource as UIElement;
}
dw.Source = _dragSource;
dw.Shim = _callback;
// System.Diagnostics.Debug.Assert(DragScope == null, "The DragDataWrapper is meant for in-proc... Sorry for asserting, just wanted to confirm.. comment out assertion if needed");
}
else
{
dragelement = args.OriginalSource as UIElement;
data = new DataObject(typeof(UIElement).ToString(), dragelement);
}
if (dragelement == null || data == null || dragelement == this._dragSource)
{
return;
}
#if DEBUG
// Add it as Text ... good for testing purposes
if (!data.GetDataPresent(DataFormats.Text))
{
data.SetData(DataFormats.Text, "abcd");
}
#endif
DragEventHandler dragOver = null;
DragEventHandler dragLeave = null;
QueryContinueDragEventHandler queryContinue = null;
GiveFeedbackEventHandler giveFeedback = null;
DragDropEffects effects = GetDragDropEffects();
DragDropEffects resultEffects;
// Inprocess Drag ...
if (DragScope != null)
{
bool previousAllowDrop = DragScope.AllowDrop;
_adorner = new DragAdorner(DragScope, (UIElement)dragelement, true, Opacity);
_layer = AdornerLayer.GetAdornerLayer(DragScope as Visual);
_layer.Add(_adorner);
if (DragScope != _dragSource)
{
DragScope.AllowDrop = true;
DragDrop.AddPreviewDragOverHandler((DependencyObject)DragScope, dragOver = new DragEventHandler(DragScope_DragOver));
DragDrop.AddPreviewDragLeaveHandler(DragScope, dragLeave = new DragEventHandler(DragScope_DragLeave));
DragDrop.AddPreviewQueryContinueDragHandler(_dragSource, queryContinue = new QueryContinueDragEventHandler(onQueryContinueDrag));
}
try
{
IsDragging = true;
this._mouseLeftScope = false;
resultEffects = DragDrop.DoDragDrop(_dragSource, data, effects);
DragFinished(resultEffects);
}
catch
{
System.Diagnostics.Debug.Assert(false);
}
if (DragScope != _dragSource)
{
DragScope.AllowDrop = previousAllowDrop;
DragDrop.RemovePreviewDragOverHandler(DragScope, dragOver);
DragDrop.RemovePreviewDragLeaveHandler(DragScope, dragLeave);
DragDrop.RemovePreviewQueryContinueDragHandler(_dragSource, queryContinue);
}
}
else
{
DragDrop.AddPreviewQueryContinueDragHandler(_dragSource, queryContinue = new QueryContinueDragEventHandler(onQueryContinueDrag));
DragDrop.AddGiveFeedbackHandler(_dragSource, giveFeedback = new GiveFeedbackEventHandler(onGiveFeedback));
IsDragging = true;
CreateDragDropWindow(dragelement);
this._dragdropWindow.Show();
try
{
resultEffects = DragDrop.DoDragDrop(_dragSource, data, effects);
}
finally { }
DestroyDragDropWindow();
DragDrop.RemovePreviewQueryContinueDragHandler(_dragSource, onQueryContinueDrag);
DragDrop.AddGiveFeedbackHandler(_dragSource, onGiveFeedback);
IsDragging = false;
DragFinished(resultEffects);
}
}