public DockButton(DockHelper parent,Func<Package, bool> dropAction, string icon)
: base(parent)
{
this.dropAction = dropAction;
SetSize(20, 20);
iconId = icon;
}
internal void ShowDockHelper()
{
if (dockHelper == null || dockHelper.Disposed)
dockHelper = new DockHelper(this);
dockHelper.IsHidden = false;
}