public MainWindow1()
 {
     InitializeComponent();
     _viewModel = (RBViewModel)base.DataContext;
     for (int i = 0; i < 4; i++)
     {
         _viewModel.AddRb("a" + i, true);
     }
 }
        public MainWindow1()
        {
            InitializeComponent();
            _viewModel = (RBViewModel)base.DataContext;

            for (int i = 0; i < 4; i++)
            {
                _viewModel.Rbs.Add(new RBVM()
                {
                    RadioBase = "a" + i, BaseCheck = true
                });
            }
        }