public class DelegateCommand : System.Windows.Input.ICommand
{
    private readonly Action m_Execute;
    private readonly Func<bool> m_CanExecute;
    public event EventHandler CanExecuteChanged;
 
    public DelegateCommand(Action execute)
        : this(execute, () => true) { /* empty */ }
 
    public DelegateCommand(Action execute, Func<bool> canexecute)
    {
        if (execute == null)
            throw new ArgumentNullException("execute");
        m_Execute = execute;
        m_CanExecute = canexecute;
    }
 
    public bool CanExecute(object p)
    {
        return m_CanExecute == null ? true : m_CanExecute();
    }
 
    public void Execute(object p)
    {
        if (CanExecute(null))
            m_Execute();
    }
 
    public void RaiseCanExecuteChanged()
    {
        if (CanExecuteChanged != null)
            CanExecuteChanged(this, EventArgs.Empty);
    }
}