Databound textbox只有在我编辑它之后才会更新。在wpf表单中使用MVVM

public class FormDataModel : INotifyPropertyChanged
{
    private string _text;

    public string Text
    {
        get { return _text; }
        set
        {
            if (_text != value)
            {
                _text = value;
                OnPropertyChanged(nameof(Text));
            }
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

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

public class FormViewModel
{
    public FormDataModel FormData { get; set; }

    public FormViewModel()
    {
        FormData = new FormDataModel();
    }
}

<TextBox Text="{Binding FormData.Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        FormViewModel viewModel = new FormViewModel();
        DataContext = viewModel;
    }
}