I found out that it's possible to add custom task panes to individual windows like e.g. the appointment with this code snippet:
public void Inspectors_NewInspector(Microsoft.Office.Interop.Outlook.Inspector Inspector)
{
Microsoft.Office.Tools.CustomTaskPane myCustomTaskPane;
if(Inspector.CurrentItem is Microsoft.Office.Interop.Outlook.AppointmentItem ) {
UserControl uc1 = MyUserControl();
myCustomTaskPane = getAddIn().CustomTaskPanes.Add(uc1, "MyPanel",Inspector);
myCustomTaskPane.DockPosition = Office.MsoCTPDockPosition.msoCTPDockPositionRight;
myCustomTaskPane.DockPositionRestrict = Office.MsoCTPDockPositionRestrict.msoCTPDockPositionRestrictNoChange;
myCustomTaskPane.Visible = true;
}
//Additionally You can add a property change listener to the current Item here
}
however, I use 'NetOffice' instead of VSTO to have the add-in compatible with various Outlook versions. And there the add-in doesn't have the CustomTaskPanes
property, and the TaskPanes.Add
property isn't overloaded to allow adding custom panes on other window than the main explorer.