IPageViewModel 不更新我的视图

Question

首先让我介绍一下我的应用。

我有MainWindowViewModel控制我的2个ViewModels:——overviewviewmodel——configureviewmodel

public class MainWindowViewModel : ViewModelBase
{
    /// <summary>
    /// The current view.
    /// </summary>
    public ViewModelBase _currentViewModel;
    /// <summary>
    /// Static instance of one of the ViewModels.
    /// </summary>
    public readonly static OverviewWindowViewModel _overviewviewmodel = new OverviewWindowViewModel();
    /// <summary>
    /// Static instance of one of the ViewModels.
    /// </summary>
    public readonly static ConfigurationWindowViewModel _configurationviewmodel = new ConfigurationWindowViewModel();
    /// <summary>
    /// The CurrentView property.  The setter is private since only this 
    /// class can change the view via a command.  If the View is changed,
    /// we need to raise a property changed event.
    /// </summary>
    public ViewModelBase CurrentViewModel
    {
        get
        {
            return _currentViewModel;
        }
        set
        {
            if (_currentViewModel == value)
                return;
            _currentViewModel = value;
            NotifyPropertyChanged("CurrentViewModel");
        }
    }
    /// <summary>
    /// Simple property to hold the 'OverviewViewCommand' - when executed
    /// it will change the current view to the 'Overview'
    /// </summary>
    public ICommand OverviewViewCommand { get; private set; }
    /// <summary>
    /// Simple property to hold the 'ConfigurationViewCommand' - when executed
    /// it will change the current view to the 'Configuration'
    /// </summary>
    public ICommand ConfigurationViewCommand { get; private set; }
    /// <summary>
    /// Default constructor.  We set the initial view-model to 'OverviewViewCommand'.
    /// We also associate the commands with their execution actions.
    /// </summary>
    public MainWindowViewModel()
    {
        CurrentViewModel = _overviewviewmodel;
        _overviewviewmodel.SwitchViewModel2Request += NavigateToView2;
        _configurationviewmodel.SwitchViewModel1Request += NavigateToView1;
        /*OverviewViewCommand = new RelayCommand(param => ExecuteOverviewViewCommand());
        ConfigurationViewCommand = new RelayCommand(param => ExecuteConfigurationViewCommand());*/
    }
    private void NavigateToView2(object sender, EventArgs e)
    {
        CurrentViewModel = _configurationviewmodel;
    }
    private void NavigateToView1(object sender, EventArgs e)
    {
        CurrentViewModel = _overviewviewmodel;
    }
}

切换在两个用户控件之间工作得很好。在"configurationviewmodel"中，我还为12个按钮定义了IPageViewModel:

private ICommand _changePageCommand;
private List<IPageViewModel> _pageViewModels;
...
PageViewModels.Add(Buttons[0]);
PageViewModels.Add(Buttons[1]);
PageViewModels.Add(Buttons[2]);
PageViewModels.Add(Buttons[3]);
PageViewModels.Add(Buttons[4]);
PageViewModels.Add(Buttons[5]);
PageViewModels.Add(Buttons[6]);
PageViewModels.Add(Buttons[7]);
PageViewModels.Add(Buttons[8]);
PageViewModels.Add(Buttons[9]);
PageViewModels.Add(Buttons[10]);
PageViewModels.Add(Buttons[11]);
CurrentPageViewModel = PageViewModels[0];
private IPageViewModel _currentPageViewModel;
public IPageViewModel CurrentPageViewModel
{
   get
   {
      return _currentPageViewModel;
   }
   set
   {
      if (_currentPageViewModel != value)
      {
         _currentPageViewModel = value;
         NotifyPropertyChanged("CurrentPageViewModel");
      }
   }
}
private void ChangeViewModel(IPageViewModel viewModel)
{
   if (!PageViewModels.Contains(viewModel))
   PageViewModels.Add(viewModel);
   CurrentPageViewModel = PageViewModels
   .FirstOrDefault(vm => vm == viewModel);
}

我的问题是，当按钮二被按下，CurrentPageViewModel必须改变为PageViewModels[1]，但这不会发生(它总是停留在PageViewModels[0])。我知道我之前的代码可以工作，因为在旧版本中我没有两个UserControls，而是两个不同的窗口。所以以前在窗口"Configurationviewmodel"工作像一个魅力，现在在用户控制"Configurationviewmodel"不起作用。

也许我给出了足够的代码来理解我的问题，如果没有，请问。

Answer 1

既然您已经确保视图模型包含在PageViewModels集合中，为什么不写:

private void ChangeViewModel(IPageViewModel viewModel)
{
    // If the view model is not in the collection, it is added.
    if (!PageViewModels.Contains(viewModel))
        PageViewModels.Add(viewModel);
    // So we can just assign the view mdoel here, since we know for sure
    // it is in the collection.
    CurrentPageViewModel = viewModel;
}

另外，您是否尝试过vm.Equals(viewModel)来比较引用?