Button doesn't become disabled when command CanExecute is false

Question

I have a simple-as-can be window with a button tied to a ViewModel with a command.

I expect the button to be disabled if MyCommand.CanExecute() is false. But it seem

Answer 1

You can try this (Microsoft.Practices.Prism.dll is necessary)

public class ViewModel
{
    public DelegateCommand ExportCommand { get; }

    public ViewModel()
    {
        ExportCommand = new DelegateCommand(Export, CanDoExptor);
    }

    private void Export()
    {
        //logic
    }

    private bool _isCanDoExportChecked;

    public bool IsCanDoExportChecked
    {
        get { return _isCanDoExportChecked; }
        set
        {
            if (_isCanDoExportChecked == value) return;

            _isCanDoExportChecked = value;
            ExportCommand.RaiseCanExecuteChanged();
        }
    }

    private bool CanDoExptor()
    {
        return IsCanDoExportChecked;
    }
}