CommandManager.InvalidateRequerySuggested() isn't fast enough. What can I do?

Question

Short Version

Calls to CommandManager.InvalidateRequerySuggested() take far longer to take effect than I would like (1-2 second delay

Answer 1

is there a way I can make CommandManager.InvalidateRequerySuggested() do it's job faster?

Yes, there is way to make it work faster!

1. Implement Command to keep / cache CanExecuteState in a boolean variable.
2. Implement RaiseCanExecuteChanged method to recalculate CanExecuteState and if it really changed to raise CanExecuteChanged event.
3. Implement CanExecute method to simply return CanExecuteState.
4. When InvalidateRequerySuggested method is invoked Command subscribers will only read CanExecuteState variable by invoking CanExecute method and check if it changed or not. That's almost zero overhead. All Commands will be disabled / enabled almost the same time.
5. All work will be done in RaiseCanExecuteChanged method that will be called only once for a Command and only for a limited set of Commands.