Question

我在WPF项目中有一个使用MVVM填充的DataGrid。当用户选择一行然后单击编辑按钮时，将打开一个窗口。我的问题是，当用户回到DataGrid时，所选项目已更改并设置为第一行！

我在视图模型中编写了这段代码：

UserInfoDAL userInfoDAL;

    public UserInfoListVM()
    {

        userInfoDAL = new UserInfoDAL();
        UserInfoCollection = new ObservableCollection<UserInfo>();
        UserInfoModelCurrent = new UserInfo();

        UserInfoSelect();
    }
   private ObservableCollection<UserInfo> _UserInfoCollection;
    public ObservableCollection<UserInfo> UserInfoCollection
    {
        get { return this._UserInfoCollection; }
        set
        {
            this._UserInfoCollection = value;
            base.OnPropertyChanged("UserInfoCollection");
        }
    }
    private int _selectedIndex;
    public int SelectedIndex
    {
        get { return _selectedIndex; }
        set
        {
            _selectedIndex = value;
            base.OnPropertyChanged("SelectedIndex");
        }
    }
    public UserInfo UserInfoModelCurrent
    {
        get;
        set;
    }public void UserInfoSelect()
    {
        SelectedIndex = _selectedIndex;
        string _errorMessage = "";

        ObservableCollection<UserInfo> _UserInfoModelCollection = new ObservableCollection<UserInfo>();
        _UserInfoModelCollection = userInfoDAL.UserInfoSelect(null, out _errorMessage);
        if (!string.IsNullOrEmpty(errorMessage))
        {
            MessageBox.Show(errorMessage, "خطا", MessageBoxButton.YesNo, MessageBoxImage.Warning, MessageBoxResult.OK);
        }
        else
        {
            UserInfoCollection = _UserInfoModelCollection;
        }
        Messenger.Default.Send(this, "UserInfoListNotify");


    }

xaml中的

：

<DataGrid 
    x:Name="GrdUserInfo" 
    Grid.Row="1" 
    ItemsSource="{Binding UserInfoCollection}" 
    MouseRightButtonDown="GrdUserInfo_MouseRightButtonDown" 
    LoadingRow="GrdUserInfo_LoadingRow" 
    AutoGeneratingColumn="GrdUserInfo_AutoGeneratingColumn" 
    SelectedItem="{Binding UserInfoModelCurrent,Mode=TwoWay}" 
    Loaded="GrdUserInfo_Loaded" 
    SelectionChanged="GrdUserInfo_SelectionChanged" 
    SelectedIndex="{Binding SelectedIndex,Mode=TwoWay,UpdateSourceTrigger=PropertyChange‌d}" 
    >

代码隐藏中的

：

     public UserInfoListView()
    {
        InitializeComponent();
        userInfoListViewModel = new UserInfoListVM();

        this.DataContext = userInfoListViewModel;

        Messenger.Default.Register<UserInfoListVM>(this, "UserInfoListNotify", x =>
        {
            DataGridSetting.DataGridPreparation(TabName, ref GrdUserInfo, userInfoListViewModel.UserInfoCollection, SelectedIndexRow);
        }
        );
    }
    public bool RestoreGridDefault = false;
    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        Window window = Window.GetWindow(this);
        window.Closing += window_Closing;
        window.KeyUp += Window_KeyDown;
    }

    private void GrdUserInfo_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
    {
        DataGridSetting.DataGridSetColumnPrperty(ref e);
       // e.Column.Width = new DataGridLength(1, DataGridLengthUnitType.Star);
    }
    private void GrdUserInfo_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
    {
        DataGridSetting.DataGridCreateContexMenu(ref GrdUserInfo, ref RestoreGridDefault, "userInfo", e);
    }
    private void GrdUserInfo_LoadingRow(object sender, DataGridRowEventArgs e)
    {
        e.Row.Header = (e.Row.GetIndex()+1).ToString();

    }
    private void GrdUserInfo_Loaded(object sender, RoutedEventArgs e)
    {
        DataGridSetting.DataGridPreparation(TabName, ref GrdUserInfo, userInfoListViewModel.UserInfoCollection, SelectedIndexRow);
    }

    private void GrdUserInfo_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        userInfoListViewModel.SelectedIndex =  GrdUserInfo.SelectedIndex;
    }

但它没有解决我的问题:(

Answer 1

令人困惑的一件事是你说你有一个“使用MVVM填充数据的网格”。

MVVM是一个代码设计/架构，其重点不在于使用代码隐藏，但你还是已经完成了。

事件处理应该从您的ViewModel完成，而不是代码隐藏。

我建议您阅读MVVM，进一步了解它是如何工作的。

This blog（在我看来）非常了解MVVM基本模式，可以帮助你。

如何在数据网格中保存选定的索引并在用户重新加载页面时设置所选项目？

1 个答案: