// 如果你用VSTO2005开发有以下办法添加右键菜单： Outlook.ExplorerClass _Explorer = null;         Office.CommandBars _CommandBars = null; object _Missing = System.Reflection.Missing.Value;          Office.CommandBarButton _ContextMenuButton = null; private void ThisApplication_Startup(object sender, System.EventArgs e)         {
                   _Explorer = (Outlook.ExplorerClass)this.ActiveExplorer();                 _CommandBars = _Explorer.CommandBars;                 _CommandBars.OnUpdate += new Microsoft.Office.Core._CommandBarsEvents_OnUpdateEventHandler(_CommandBars_OnUpdate);         } void _CommandBars_OnUpdate()         {
   foreach (Office.CommandBar bar in _CommandBars)             {
   if (bar.Name == "Context Menu")                 {
   // we found the context menu                     Office.MsoBarProtection oldProtection = bar.Protection;                     bar.Protection = Microsoft.Office.Core.MsoBarProtection.msoBarNoProtection;                     _ContextMenuButton = (Office.CommandBarButton)bar.Controls.Add(Office.MsoControlType.msoControlButton, 1, _Missing, _Missing, true);                     _ContextMenuButton.Style = Microsoft.Office.Core.MsoButtonStyle.msoButtonIconAndCaption;                     _ContextMenuButton.TooltipText = "Isabella's Context menu....";                     _ContextMenuButton.BeginGroup = true;                     _ContextMenuButton.Caption = "Click me...";                     _ContextMenuButton.Visible = true;                     _ContextMenuButton.Click += new Microsoft.Office.Core._CommandBarButtonEvents_ClickEventHandler(_ContextMenuButton_Click);                     bar.Protection = oldProtection;                 }             }         } void _ContextMenuButton_Click(Microsoft.Office.Core.CommandBarButton Ctrl, ref bool CancelDefault)         {
               MessageBox.Show("Hey, you clicked the Contextbutton !");         }

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