Question

Icommand contains two methods and one event.

What the two methods do is clear, but I can’t understand what the event does that is provided in ICommand.

When is the CanExecuteChanged event raised?

The below explanation is on MSDN but I can’t understand it.

CanExecuteChanged is raised if the command manager that
centralizes the commanding operations detects a change in the command
source that might invalidate a command that has been raised but not
yet executed by the command binding.

Can you please explain this in simple terms?

Thanks……

Answer 1

CanExecuteChanged is raised when the CanExecute method of an ICommand gets changed

In some 3rd party libraries, the CanExecuteChanged event also gets raised if the CanExecute parameters raise a PropertyChanged event. For example, MVVM Light Toolkit’s RelayCommand raises the CanExecuteChanged event if the CanExecute parameters raise a PropertyChanged event, while Prism’s DelegateCommand does not.