数据绑定(使用MVVM模式)到DataGrid的RowDetailsTemplate中的WPF组合框的问题

public class MyViewModel : INotifyPropertyChanged
{
    private ObservableCollection<string> _options;
    private string _selectedOption;

    public ObservableCollection<string> Options
    {
        get { return _options; }
        set
        {
            _options = value;
            OnPropertyChanged(nameof(Options));
        }
    }

    public string SelectedOption
    {
        get { return _selectedOption; }
        set
        {
            _selectedOption = value;
            OnPropertyChanged(nameof(SelectedOption));
        }
    }

    // 实现INotifyPropertyChanged接口的代码...

    // 构造函数中初始化选项列表
    public MyViewModel()
    {
        Options = new ObservableCollection<string>
        {
            "Option 1",
            "Option 2",
            "Option 3"
        };
    }
}

<DataGrid ItemsSource="{Binding DataItems}">
    <DataGrid.RowDetailsTemplate>
        <DataTemplate>
            <StackPanel>
                <ComboBox ItemsSource="{Binding DataContext.Options, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"
                          SelectedValue="{Binding DataContext.SelectedOption, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"
                          SelectedValuePath="."/>
            </StackPanel>
        </DataTemplate>
    </DataGrid.RowDetailsTemplate>
</DataGrid>