通过

Command availability

  • 项目

Applies to: yesVisual Studio noVisual 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

The Visual Studio context determines which commands are available. The context can change depending on the current project, the current editor, the VSPackages that are loaded, and other aspects of the integrated development environment (IDE).

Command contexts

The following command contexts are the most common:

  • IDE: Commands provided by the IDE are always available.

  • VSPackage: VSPackages can define when commands are to be displayed or hidden.

  • Project: Project commands appear only for the currently selected project.

  • Editor: Only one editor can be active at a time. Commands from the active editor are available. An editor works closely with a language service. The language service must process its commands in the context of the associated editor.

  • File type: An editor can load more than one type of file. The available commands can change depending on the file type.

  • Active window: The last active document window sets the user interface (UI) context for key bindings. However, a tool window that has a key-binding table that resembles the internal web browser could also set the UI context. For multi-tabbed document windows such as the HTML editor, every tab has a different command context GUID. After a tool window is registered, it is always available on the View menu.

  • UI context: UI contexts are identified by the values of the VSConstants.UICONTEXT class, for example, SolutionBuilding_guid when the solution is being built, or Debugging_guid when the debugger is active. Multiple UI contexts can be active at the same time.

Define custom context GUIDs

If an appropriate command context GUID is not already defined, you can define one in your VSPackage and then program it to be active or inactive as required to control the visibility of your commands:

  1. Register context GUIDs by calling the GetCmdUIContextCookie method.

  2. Get the state of a context GUID by calling the IsCmdUIContextActive method.

  3. Turn context GUIDs on and off by calling the SetCmdUIContext method.

Caution

Make sure that your VSPackage does not affect any existing context GUIDs because other VSPackages may depend on them.

See also