如何防止功能区控件（winforms）上的Infragistics ComboBoxTool中不必要的工具提示弹出窗口

public class MyCreation : IUIElementCreationFilter  {

    private readonly int max;

    public MyCreation()
    {
    }

    public MyCreation(int toolTipMaxWidth)
    {
        max = toolTipMaxWidth;
    }

    public void AfterCreateChildElements(UIElement parent)
    {
        parent.ToolTipItem = new MyToolTipItem(max);
    }

    public bool BeforeCreateChildElements(UIElement parent)
    {
        return false;
    }
}


public class MyToolTipItem : IToolTipItem   {
    private readonly int max;

    public MyToolTipItem(int maxWidth)
    {
        max = maxWidth;
    }

    public MyToolTipItem()
    {
    }

    public ToolTipInfo GetToolTipInfo(Point mousePosition, UIElement element, UIElement previousToolTipElement,
                                  ToolTipInfo toolTipInfoDefault)
    {
        // set tooltip info for ribbon ApplicationMenuButton
        var app = element as ApplicationMenuButtonUIElement;
        if (app != null)
        {
            var appmenu = ((UltraToolbarsDockAreaUIElement) ((app.Parent).Parent)).ToolbarsManager.Ribbon.ApplicationMenu;
            if (max > 0)
                toolTipInfoDefault.MaxWidth = max;
            toolTipInfoDefault.Title = appmenu.ToolTipTitle;

            string tooltiptex = appmenu.ToolTipText;
            if (!string.IsNullOrEmpty(appmenu.ToolTipTextFormatted))
            {
                toolTipInfoDefault.ToolTipTextStyle = ToolTipTextStyle.Formatted;
                tooltiptex = appmenu.ToolTipTextFormatted;
            }
            toolTipInfoDefault.ToolTipText = tooltiptex;
        }

        // set tooltip info for tools
        if (element.ToolTipItem != null && UIElement.IsContextOfType(element.GetContext(), typeof (ToolBase)))
        {
            var tool = (ToolBase) element.GetContext(typeof (ToolBase));
            var loc = tool.ToolbarsManager.DockWithinContainer.PointToScreen(new Point(0, 0));
        loc.Offset(tool.UIElement.Rect.Location.X, 185);

            if (max > 0)
                toolTipInfoDefault.MaxWidth = max;
        toolTipInfoDefault.Title = tool.SharedProps.ToolTipTitle;
        string tooltiptex = tool.SharedProps.ToolTipText;
            if (!string.IsNullOrEmpty(tool.SharedProps.ToolTipTextFormatted))
            {
                toolTipInfoDefault.ToolTipTextStyle = ToolTipTextStyle.Formatted;
                tooltiptex = tool.SharedProps.ToolTipTextFormatted;
            }
            toolTipInfoDefault.ToolTipText = tooltiptex;
            toolTipInfoDefault.DisplayStyle = Infragistics.Win.ToolTipDisplayStyle.Office2007;
            toolTipInfoDefault.Location = loc;
        }
        return toolTipInfoDefault;
    }