清除控件某个事件的所有响应函数

public void ClearEvent(System.Windows.Forms.Control control, string eventName)
{
    if (control == null)
        return;

    try
    {
        Type cType = control.GetType();
        EventInfo ei = cType.GetEvent(
            eventName,
            BindingFlags.Public |
            BindingFlags.NonPublic |
            BindingFlags.Instance);

        if (ei == null)
            return;
        FieldInfo fi = ei.DeclaringType.GetField(eventName,
            BindingFlags.Public |
            BindingFlags.NonPublic |
            BindingFlags.Instance);

        if (fi != null)
            fi.SetValue(control, null);
    }
    catch { }
}