UltraToolTipManager :
protected override void Dispose(bool disposing)
{
    if (disposing)
    {
        if ((this.extenderPropertyTable != null) && (this.extenderPropertyTable.Count > 0))
        {
            object[] array = new object[this.ExtenderPropertyTable.Count];
            this.ExtenderPropertyTable.Keys.CopyTo(array, 0);
            foreach (Control control in array)
            {
                this.SetUltraToolTip(control, null);
            }
        }
        this.DisposeToolTip();
        if (this.license != null)
        {
            this.license.Dispose();
            this.license = null;
        }
    }
    base.Dispose(disposing);
}

 
public void SetUltraToolTip(Control control, UltraToolTipInfo toolTipInfo)
{
    if (((IExtenderProvider) this).CanExtend(control))
    {
        UltraToolTipInfo info = this.ExtenderPropertyTable[control] as UltraToolTipInfo;
        if (info != null)
        {
            info.SubObjectPropChanged -= this.SubObjectPropChangeHandler;
            this.UnhookExtenderComponent(control);
            this.ExtenderPropertyTable.Remove(control);
            this.DisposeToolTipIfOwned(control);
        }
        if (toolTipInfo != null)
        {
            toolTipInfo.SubObjectPropChanged += this.SubObjectPropChangeHandler;
            this.HookExtenderComponent(control);
            this.ExtenderPropertyTable.Add(control, toolTipInfo);
        }
    }
}

 
private void DisposeToolTipIfOwned(Control owner)
{
    if ((this.tooltip != null) && (this.tooltip.OwningControl == owner))
    {
        this.DisposeToolTip();
    }
}

 private void DisposeToolTip()
{
    if (this.tooltip != null)
    {
        this.tooltip.Hide();
        this.tooltip.Dispose();
        this.tooltip = null;
    }
}