If the given view is not from the currently active document; -or-
If the active document is currently modifiable (i.e. with an active transaction); -or-
If the active document is currently in read-only state; -or-
During either ViewActivating or ViewActivated event; -or-
During any pre-action kind of event, such as DocumentSaving, etc.
Remarks
This method requests to change the active view by posting a message asynchronously. Unlike setting the ActiveView property, this will not make the change in active view immediately. Instead the request will be posted to occur when control returns to Revit from the API context. This method is permitted to change the active view from the Idling event or an ExternalEvent callback.
The active view cannot be changed when:
There is an open transaction in the currently active document.