protected override void OnClick() { ESRI.ArcGIS.esriSystem.UID uid = new ESRI.ArcGIS.esriSystem.UIDClass(); // this is from Config.esriaddinx (<DockableWindow id="Test_TestingAddin1_DockableWindow1" class="testbrowser+AddinImpl"...) uid.Value = "Test_TestingAddin1_DockableWindow1"; ESRI.ArcGIS.Framework.IDockableWindow dw = ArcMap.DockableWindowManager.GetDockableWindow(uid); if (!dw.IsVisible()) dw.Show(true); }