When is canexecutechanged called

Ask a question. Quick access. Search related threads. Remove From My Forums. Answered by:. Archived Forums. Sign in to vote. Lloyd Sheen. Monday, March 7, PM. Hi Lloyd, The commandmanager decides when something has changed based on user interaction, essentially. Not many devs use routeduicommands. Routeduicommands target whatever has focus or what you explicitly set as the commandtarget.

You might find setting commandtarget makes a significant difference. Hope that helps. Marked as answer by sqlguy Wednesday, March 9, PM. Wednesday, March 9, AM. The RequerySuggested event is raised whenever conditions are met that may change the whether the command should execute, such as a change in keyboard focus. Generally, the command source will listen for this event and query the RoutedCommand by way of the CanExecute method.

Most command sources will disable themselves if the command cannot be executed, as part of their command binding. An example of this is when a MenuItem grays itself out when the command cannot be executed. In some situations, the CommandManager is unaware of a change in conditions that alters the ability of a command to execute. Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services.

If the value must be persistent consider using SharedPreferences. Hope this helps somebody anyway, Cheers, Will. The ItemsSource of a grid must be IEnumerable. Only authorized users can answer the question.

Please sign in first, or register a free account. Not the answer you're looking for? Browse other questions tagged : c. Related Answers. Top Answers Related To c ,. RequerySuggested event is raised. According to the documentation, this will be In practical terms, this just means that you don't need to worry about when CanExecute is called: WPF will invoke it when it thinks it is appropriate, and in my experience this will almost always cover your requirements.

The exception to this is if you have a background task that will cause CanExecute to change it's return value based on something that is not triggered by the UI. Login using GitHub Register. Ask a Question. Add cb ; okButton. Please log in or register to add a comment.