Source Control Configuration Details
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
In order to implement source control, you need to properly configure your project system or editor to do the following:
Request permission to transition to changed state
Request permission to save a file
Request permission to add, remove, or rename files in the project
Request Permission to Transition to Changed State
A project or editor must request permission to transition to the changed (dirty) state by calling IVsQueryEditQuerySave2. Each editor that implements IsDocDataDirty must call QueryEditFiles and receive approval to change the document from the environment before returning True for IsDocDataDirty. A project is essentially an editor for a project file, and as a result, has the same responsibility for implementing changed-state tracking for the project file as a text editor does for its files. The environment handles the changed state of the solution, but you must handle the changed state of any object the solution references but does not store, like a project file or its items. In general, if your project or editor is responsible for managing persistence for an item, then it is responsible for implementing changed-state tracking.
In response to the IVsQueryEditQuerySave2::QueryEditFiles call, the environment can do the following:
Reject the call to change, in which case the editor or project must remain in the unchanged (clean) state.
Indicate that the document data should be reloaded. For a project, the environment will reload the data for the project. An editor must reload the data from disk through its ReloadDocData implementation. In either case, the context in the project or editor can change when the data is reloaded.
It is a complex and difficult task to retrofit appropriate
IVsQueryEditQuerySave2::QueryEditFilescalls onto an existing code base. As a result, these calls should be integrated during the creation of the project or editor.
Request Permission to Save a File
Before a project or editor saves a file, it must call QuerySaveFile or QuerySaveFiles. For project files, these calls are automatically completed by the solution, which knows when to save a project file. Editors are responsible for making these calls unless the editor implementation of IVsPersistDocData2 uses the helper function SaveDocDataToFile. If your editor implements IVsPersistDocData2 in this way, then the call to IVsQueryEditQuerySave2::QuerySaveFile or IVsQueryEditQuerySave2::QuerySaveFiles is made for you.
Note
Always make these calls preemptively—that is, at a time when your editor is able to receive a cancel.
Request Permission to Add, Remove, or Rename Files in the Project
Before a project can add, rename, or remove a file or directory, it must call the appropriate IVsTrackProjectDocuments2::OnQuery* method to request permission from the environment. If permission is granted, then the project must complete the operation and then call the appropriate IVsTrackProjectDocuments2::OnAfter* method to notify the environment that the operation is complete. The project must call the methods of the IVsTrackProjectDocuments2 interface for all files (for example, special files) and not just the parent files. File calls are mandatory, but directory calls are optional. If your project has directory information, then it should call the appropriate IVsTrackProjectDocuments2 methods, but if it does not have this information, then the environment will infer directory information.
The project should not call the methods of IVsTrackProjectDocuments2 at project open or close. Listeners that want this information at startup can wait for the OnAfterOpenSolution event and iterate through the solution to find the information they need. On shutdown, this information is not needed. IVsTrackProjectDocuments2 is provided from the SVsTrackProjectDocuments.
For each add, rename, and remove action, there is an OnQuery* method and an OnAfter* method. Call the OnQuery* method to ask permission to add, rename, or remove the file or directory. Call the OnAfter* method after the file or directory has been added, renamed, or removed and the project state reflects the new state.