Edit Actions are operations that are invoked from the Select Tool and can be performed on a DgnPlatform::HitPath or a view with no additional input from the user. They are activated by the user from a right-click popup menu or from a key defined for Positional Keyboard Navigation.
To add EditActions for your application, you first must implement the DgnPlatform::IEditActionSource interface. Next, you install your DgnPlatform::IEditActionSource by calling MstnEventManager::AddEditActionSource. Whenever the user presses the right mouse button from the Select Tool or presses a positional key, MicroStation will call the TestPath method of each installed DgnPlatform::IEditActionSource so that each can examine the current path and decide whether to add EditActions for it.
The list of current Edit Actions (provided by DgnPlatform::IEditActionSource) is sorted by "priority". In the case of a right click, their SetupMenu methods are called, and the resultant popup menu is presented to the user, who will then possibly select an appropriate Edit Action. In the case of a Positional Keyboard Navigation key, the corrensponding Edit Action is determined. If and when the user selects an Edit Action, either its associated CommandNumber (if present) will be queued for processing or its PerformAction method will be called.
Edit Actions are associated with MDL applications, but they must be implemented in C++, VBA, or C#.