public override void OnClick()
        {
            if (_hook == null)
            {
                return;
            }
            if (_hook.MainUserControl == null)
            {
                return;
            }

            if (!File.Exists(ModDBOperate._QueryConfigXmlPath))
            {
                return;
            }
            //读取配置文件信息
            XmlDocument pXmlDoc = new XmlDocument();

            pXmlDoc.Load(ModDBOperate._QueryConfigXmlPath);
            string  strSearch = "//LoadDataConfig/LoadItem[@ItemText='927ZT']/NodeItem";
            XmlNode pXmlnode  = pXmlDoc.SelectSingleNode(strSearch);

            if (pXmlnode == null)
            {
                return;
            }
            //获取节点的NodeKey
            string strNodeKey = pXmlnode.Attributes["NodeKey"].Value;

            pXmlDoc = null;
            GeoLayerTreeLib.LayerManager.UcDataLib pLayerTree = _hook.LayerTree as GeoLayerTreeLib.LayerManager.UcDataLib;
            DevComponents.AdvTree.Node             pNode      = pLayerTree.GetNodeByNodeKey(strNodeKey);

            //changed by chulili 20111118 加载或卸载指定NodeKey下面的数据
            if (base._Checked == false)                                          //按钮先前未被按下
            {
                pNode.SetChecked(true, DevComponents.AdvTree.eTreeAction.Mouse); //加载数据
                if (pNode.Checked)                                               //若数据被正确加载
                {
                    base._Checked = true;                                        //按钮置于按下状态
                }
            }
            else //按钮先前是按下的状态
            {
                pNode.SetChecked(false, DevComponents.AdvTree.eTreeAction.Mouse);   //卸载数据
                if (!pNode.Checked)        //若数据被成功卸载
                {
                    base._Checked = false; //按钮置于非按下状态
                }
            }



            ////调用函数,加载该节点内容
            //UserControlSMPD pUserControl = _hook.MainUserControl as UserControlSMPD;
            //if (pUserControl != null)
            //{
            //    pUserControl.AddDataDir(strNodeKey);
            //}
        }