protected override void OnHandleDestroyed(EventArgs e)
{
base.OnHandleDestroyed(e);
this.toolTipProvider.Destroy();
this.toolTipProvider = null;
this.toolTipId = 0;
}
protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
this.toolTipProvider = new DataGridToolTip(this);
this.toolTipProvider.CreateToolTipHandle();
this.toolTipId = 0;
base.PerformLayout();
}