WPF DataGrid CanUserAddRows = True

我似乎有一个问题,DataGrid通过接口本身添加行.以下是UI的屏幕截图:

如您所见,数据库中找到了0行,因此DataGrid右侧没有显示任何内容.但是id就像那里有一个空行,用于手动添加行.该DataGrid.CanUserAddRows设置为True,但没有任何效果.这是xaml为了DataGrid,我已经冒昧地删除了一些代码,使其变小.

PrivilegeDetailsView.xaml

    
        
            
                
                    
                        
                    
                
            
            
            
                
                    
                
            
            ...
        
    

PrivilegeDetailsView.xaml.cs

public partial class PrivilegeDetailsView : IPrivilegeDetailsView
{
    public PrivilegeDetailsView() { InitializeComponent(); }

    public DataGrid PrivilegesOnObjectsDataGrid { get { return PrivilegeDataGrid; } }

    public IViewModel ViewModel
    {
        get { return (IViewModel)DataContext; }
        set { DataContext = value; }
    }
}

下面是ViewModel (VM)对xaml View上面:

PrivilegeDetailsViewModel.cs

public class PrivilegeDetailsViewModel : ViewModelBase, IPrivilegeDetailsViewModel
{
    private readonly IEventAggregator _eventAggregator;
    private readonly IPrivilegeViewModel _privilegeViewModel;
    private readonly IRoleHasPrivilegeOnObjectViewModelAdapterRepository _roleHasPrivilegeOnObjectViewModelAdapterRepository;
    private ObservableCollection _rolesHasPrivilegesOnObjects;

    public PrivilegeDetailsViewModel(IPrivilegeDetailsView view,
                                     IRoleHasPrivilegeOnObjectViewModelAdapterRepository roleHasPrivilegeOnObjectViewModelAdapterRepository,
                                     IPrivilegeViewModel privilegeViewModel,
                                     IEventAggregator eventAggregator) : base(view)
    {
        _roleHasPrivilegeOnObjectViewModelAdapterRepository = roleHasPrivilegeOnObjectViewModelAdapterRepository;
        _privilegeViewModel = privilegeViewModel;
        _eventAggregator = eventAggregator;
        Initialize();
    }

    protected override sealed void Initialize()
    {
        _privilegeViewModel.PropertyChanged += PrivilegeViewModelOnPropertyChanged;
        _eventAggregator.GetEvent().Subscribe(ToggleSelectPrivilege);
        ...
    }

    public new IPrivilegeDetailsView View
    {
        get { return (IPrivilegeDetailsView)base.View; }
    }

    public ObservableCollection RolesHasPrivilegesOnObjects
    {
        get { return _rolesHasPrivilegesOnObjects; }
        set
        {
            _rolesHasPrivilegesOnObjects = value;
            OnPropertyChanged();
        }
    }

    public void Save()
    {
        if(RolesHasPrivilegesOnObjects == null) return;
        _roleHasPrivilegeOnObjectViewModelAdapterRepository.SaveChanges(RolesHasPrivilegesOnObjects);
    }        

    private void ToggleExecutePrivilege(object obj)
    {
        var toggle = !View.PrivilegesOnObjectsDataGrid.SelectedItems.Cast()
                          .All(x => x.HasExecute);
        foreach(var selectedItem in View.PrivilegesOnObjectsDataGrid
                                        .SelectedItems
                                        .Cast()
                                        .Where(selectedItem => selectedItem.Object
                                                                           .CanHavePrivilege("EXECUTE"))) {
                                            selectedItem.HasExecute = toggle; 
                                        }
    }

    ...

    private void PrivilegeViewModelOnPropertyChanged(object s, PropertyChangedEventArgs e)
    {
        switch(e.PropertyName)
        {
            //When the SelectedSchema changes in the parent VM, I get the new rows to be shown in the DataGrid.
            case "SelectedSchema":
                RolesHasPrivilegesOnObjects = _roleHasPrivilegeOnObjectViewModelAdapterRepository
                                                  .GetPrivilegesOnObjectsAssociatedWith((IRoleEntityViewModel)_privilegeViewModel.SelectedRole,
                                                  (IContainerEntityViewModel)_privilegeViewModel.SelectedSchema);
                break;
        }
    }
}

这是VM对于每一行DataGrid

RoleHasPrivilegeOnObjectEntityViewModel.cs

public class RoleHasPrivilegeOnObjectEntityViewModel : EntityViewModelBase, 
                                                       IRoleHasPrivilegeOnObjectListItemViewModel
{
    private readonly RoleHasPrivilegesOnObject _roleHasPrivilegesOnObject;

    public RoleHasPrivilegeOnObjectEntityViewModel(RoleHasPrivilegesOnObject roleHasPrivilegesOnObject)
    {
        _roleHasPrivilegesOnObject = roleHasPrivilegesOnObject;
        Role = new RoleEntityViewModel(_roleHasPrivilegesOnObject.Role);
        Object = new ObjectEntityViewModel(_roleHasPrivilegesOnObject.Object);
    }

    public override EntityType EntityType { get { return EntityType.NONE; } }

    public override RoleHasPrivilegesOnObject OriginalEntity { get { return _roleHasPrivilegesOnObject; } }

    public IRoleEntityViewModel Role { get; set; }

    public IObjectEntityViewModel Object { get; set; }

    public string ToolTip { get { return _roleHasPrivilegesOnObject.ToolTip; } }

    public bool HasExecute
    {
        get { return _roleHasPrivilegesOnObject.HasExecute; }
        set
        {
            _roleHasPrivilegesOnObject.HasExecute = value;
            OnPropertyChanged();
        }
    }

    public bool CanHaveExecute { get { return _roleHasPrivilegesOnObject.CanHaveExecute; } }

    public override string Icon { get { return Object != null ? Object.Icon : string.Empty; } }

    public override string NAME
    {
        get { return _roleHasPrivilegesOnObject.NAME; }
        set
        {
            _roleHasPrivilegesOnObject.NAME = value;
            OnPropertyChanged();
        }
    }

    ...
}

我知道这是很多代码,我已经剥离了很多并放置了几个点(...)来表明存在更多的代码.注意:我使用EF5和PRISM

如何DataGrid通过GUI接受新行？