word addin 向各位大神求解

Question

运行一下程序 为什吗老有文档不断弹出呀 无穷无极的文档自动弹出 求解呀！！！！！！
        void btn_Click(Office.CommandBarButton Ctrl, ref bool CancelDefault)
        {
            MessageBox.Show("My button is clicked!");        }
        
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            Word.Application wordApp = new Microsoft.Office.Interop.Word.Application();
            wordApp.Visible = true;            Microsoft.Office.Core.CommandBar commandBar = wordApp.CommandBars.Add("my",Office.MsoBarPosition.msoBarTop,false ,true);
            commandBar.Visible = true;            Office.CommandBarButton btn = commandBar.Controls.Add(Office.MsoControlType.msoControlButton,
                missing, missing, missing, true) as Office.CommandBarButton;
            btn.Caption = "My Button";
            btn.Tag = "MyButton";
            btn.Style = Office.MsoButtonStyle.msoButtonCaption;            btn.Click += new _CommandBarButtonEvents_ClickEventHandler(btn_Click);                  }
private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
          
        }