Question

这是我的观点主要：

XAML查看主要内容：

<DataGrid AutoGenerateColumns="false" 
          SelectedItem="{Binding Selectedrole}"
          ItemsSource="{Binding RoleList}">
  <Button Content="Add Role"
          Command="{Binding  AddRole}"
          Height="35"/>
</DataGrid>

ViewModel Main：

public RoleManagementViewModel()
{
    roleList = new ObservableCollection<UserRoleClass>(WCFclient.GetAllRoles());
    _addRole = new RelayCommand<string>(AddRoleFunction);           
}    

private void AddRoleFunction(object obj)
{
    if (!Application.Current.Windows.OfType<SelectionCompartementView>().Any())
    {              
        AddRoleView winAddRole = new AddRoleView();
        winAddRole.DataContext = new AddRoleViewModel();
        winAddRole.Show();
        winAddRole.Topmost = true;
        winAddRole.Focus();
    }           
}

public ObservableCollection<UserRoleClass> RoleList
{
    get { return roleList; }
    set
    {
        roleList = value;
        OnPropertyChanged("RoleList");
    }
}

视图添加角色：

Xaml Add-Role：

<Button x:Name="button1"
        Command="{Binding SaveRole}"
        CommandParameter="{Binding ElementName=AddRole}"/>

ViewModel添加角色：

public AddRoleViewModel()
{
    _addOrUpdate = new UserRoleClass();
    _addOrUpdate = new UserRoleClass();
    saveRole = new RelayCommand<Window>(addFunc);
}

private void addFunc(Window window)
{
    UserRoleClass newRole = new UserRoleClass()
    {
        name = AddOrUpdate.name,
        description = AddOrUpdate.description,
    };                                             
    int resultSave = WCFclient.saveRole(newRole);          
    if (resultSave == 0)
    {
        String UpdateInformation0 = "Role is saved successfully";
        string sCaption = "Save Role";
        MessageBoxButton btnMessageBox = MessageBoxButton.OK;
        MessageBoxImage icnMessageBox = MessageBoxImage.Information;
        MessageBoxResult rsltMessageBox = MessageBox.Show(
            UpdateInformation0, sCaption, btnMessageBox, icnMessageBox);
    }
    if (window != null)
    {
        window.Close();
    }
}    

private ICommand saveRole;
public ICommand SaveRole
{
    get { return saveRole; }
}

它运行正常：当我添加一个新的Role时，Add-Role的视图关闭并返回到主视图，我在数据库中有结果...但不在{{1}中在MainView中。

如何直接刷新？

Answer 1

首先，为什么你有以下两行？ _addOrUpdate = new UserRoleClass();

其次，当您保存新角色时，您似乎正在调用将其保存到数据库的WCF服务。
您使用了一个可观察的集合，该集合应该在您添加时更新，但我没有看到您的代码将新角色添加到RoleList。

Answer 2

最快的方法是使用类似的东西。

 public AddRoleViewModel(Action<UserRoleClass> onAdded = null)
    {
        _addOrUpdate = new UserRoleClass();          
        _addOrUpdate = new UserRoleClass();
        _onAdded = onAdded;
        saveRole = new RelayCommand<Window>(addFunc);           
    }

    private void addFunc(Window window)
    {
        UserRoleClass newRole = new UserRoleClass()
        {
            name = AddOrUpdate.name,
            description = AddOrUpdate.description,
        };                                             
             int resultSave = WCFclient.saveRole(newRole);          
            if (resultSave == 0)
             {
                 String UpdateInformation0 = "Role is saved successfully";
                 string sCaption = "Save Role";
                 MessageBoxButton btnMessageBox = MessageBoxButton.OK;
                 MessageBoxImage icnMessageBox = MessageBoxImage.Information;
                 MessageBoxResult rsltMessageBox = MessageBox.Show(UpdateInformation0, sCaption, btnMessageBox, icnMessageBox);
             }           

         }
         _onAdded?.Invoke(newRole);           
         if (window != null)
         {

             window.Close();
         }

当您创建ViewModel

时

 new AddRoleViewModel(newItem=>{ RoleList.Add(newItem); });

但我不能说我喜欢这个架构。如果可能想要查看某种messenger service

Answer 3

这是将datagrid绑定到可观察集合的常见问题。如果集合内容发生更改，则集合更改时更新绑定。在将新的UserRole添加到RoleList之后，最好的方法是使用像这样的“深度”可观察集合：

public sealed class DeepObservableCollection<T>
    : ObservableCollection<T> where T : INotifyPropertyChanged {

    public event PropertyChangedEventHandler ItemPropertyChanged;

    public DeepObservableCollection() {
        CollectionChanged += DeepObservableCollection_CollectionChanged;
    }

    public DeepObservableCollection(ObservableCollection<T> collection)
        : base(collection) {
        CollectionChanged += DeepObservableCollection_CollectionChanged;
    }

    public DeepObservableCollection( List<T> collection )
        : base( collection ) {
        CollectionChanged += DeepObservableCollection_CollectionChanged;
    }

    void DeepObservableCollection_CollectionChanged( object sender, NotifyCollectionChangedEventArgs e ) {
        if ( e.NewItems != null ) {
            foreach ( var item in e.NewItems ) {
                var notifyPropertyChanged = item as INotifyPropertyChanged;
                if ( notifyPropertyChanged != null ) notifyPropertyChanged.PropertyChanged += item_PropertyChanged;
            }
        }
        if ( e.OldItems != null ) {
            foreach ( Object item in e.OldItems ) {
                var notifyPropertyChanged = item as INotifyPropertyChanged;
                if ( notifyPropertyChanged != null ) notifyPropertyChanged.PropertyChanged -= item_PropertyChanged;
            }
        }
    }
    void item_PropertyChanged( object sender, PropertyChangedEventArgs e ) {
        NotifyCollectionChangedEventArgs a = new NotifyCollectionChangedEventArgs( NotifyCollectionChangedAction.Reset );
        OnCollectionChanged( a );

        ItemPropertyChanged?.Invoke( sender, e );
    }
}

你的UserRoleClass必须实现INotifyPropertyChanged（可能使用ObservableObject），但这就是所需要的。通过绑定添加新用户角色datagrid更新时。

添加新的客户MVVM WPF后刷新Datagrid

3 个答案: