private static void TargetElementChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
DragControlHelper Helper = d as DragControlHelper;
if (Helper == null)
{
return;
}
FrameworkElement oldTarget = e.OldValue as FrameworkElement;
Helper.DetachTatgetEvents(oldTarget);
bool isAutoReset = oldTarget != null?GetIsAutoResetES(oldTarget) : false;
FrameworkElement newTarget = e.NewValue as FrameworkElement;
if (newTarget == null ||
newTarget is DragControlHelper ||
newTarget.RenderSize.IsEmpty ||
double.IsNaN(newTarget.RenderSize.Width) ||
double.IsNaN(newTarget.RenderSize.Height) ||
!GetIsSelectable(newTarget))
{
Helper.Visibility = Visibility.Collapsed;
if (isAutoReset)
{
//重置可编辑属性
SetIsEditable(oldTarget, false);
SetIsSelectable(oldTarget, false);
}
return;
}
Helper.AttachTatgetEvents(newTarget);
int Zindex = Panel.GetZIndex(newTarget);
if (Zindex >= Panel.GetZIndex(Helper))
{
Panel.SetZIndex(Helper, Zindex + 1);
}
double Y = CorrectDoubleValue(Canvas.GetTop(newTarget));
double X = CorrectDoubleValue(Canvas.GetLeft(newTarget));
Canvas.SetTop(Helper, Y);
Canvas.SetLeft(Helper, X);
Helper.Width = newTarget.ActualWidth;
Helper.Height = newTarget.ActualHeight;
}
private static void TargetElementChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
DragControlHelper Helper = d as DragControlHelper;
if (Helper == null)
{
return;
}
FrameworkElement Target = e.OldValue as FrameworkElement;
Helper.DetachTatgetEvents(Target);
Target = e.NewValue as FrameworkElement;
if (Target == null ||
Target is DragControlHelper ||
Target.RenderSize.IsEmpty ||
double.IsNaN(Target.RenderSize.Width) ||
double.IsNaN(Target.RenderSize.Height) ||
!GetIsSelectable(Target))
{
Helper.Visibility = Visibility.Collapsed;
return;
}
Helper.AttachTatgetEvents(Target);
int Zindex = Panel.GetZIndex(Target);
if (Zindex >= Panel.GetZIndex(Helper))
{
Panel.SetZIndex(Helper, Zindex + 1);
}
double Y = CorrectDoubleValue(Canvas.GetTop(Target));
double X = CorrectDoubleValue(Canvas.GetLeft(Target));
Canvas.SetTop(Helper, Y);
Canvas.SetLeft(Helper, X);
Helper.Width = Target.ActualWidth;
Helper.Height = Target.ActualHeight;
}