Xamarin表单选取器值绑定

Picker picker = new Picker();
picker.ItemsSource = new List<string> { "Option 1", "Option 2", "Option 3" };

public class MyModel : INotifyPropertyChanged
{
    private string selectedOption;
    public string SelectedOption
    {
        get { return selectedOption; }
        set
        {
            if (selectedOption != value)
            {
                selectedOption = value;
                OnPropertyChanged(nameof(SelectedOption));
            }
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

MyModel model = new MyModel();

picker.SetBinding(Picker.SelectedItemProperty, new Binding("SelectedOption", BindingMode.TwoWay));