To reproduce:
public Form1()
{
InitializeComponent();
this.radTreeView1.AllowDragDrop = true;
this.radTreeView2.AllowDragDrop = true;
for (int i = 0; i < 5; i++)
{
this.radTreeView1.Nodes.Add("Node1." + i);
this.radTreeView2.Nodes.Add("Node2." + i);
}
this.radTreeView1.ScreenTipNeeded += radTreeView1_ScreenTipNeeded;
this.radTreeView2.ScreenTipNeeded += radTreeView1_ScreenTipNeeded;
}
RadOffice2007ScreenTipElement _screenTip = new RadOffice2007ScreenTipElement();
private void radTreeView1_ScreenTipNeeded(object sender, Telerik.WinControls.ScreenTipNeededEventArgs e)
{
_screenTip.CaptionLabel.Text = "Caption";
_screenTip.MainTextLabel.Text = "text";
_screenTip.AutoSize = true;
e.Delay = 2000;
e.Item.ScreenTip = _screenTip;
}
Steps:
1. Drag a node from the first RadTreeView to the other while the screen-tip is shown for the dragged node.
2. When the screen-tip is about to be hidden, the error occurs.
Workaround:
private void radTreeView1_DragStarting(object sender, RadTreeViewDragCancelEventArgs e)
{
if (_screenTip.IsElementVisible)
{
this.radTreeView1.Behavior.HideScreenTip();
}
}