WPF MMV pattern.send活动属性到另一个视图模型

Question

我正在尝试用MVVM模式开发一个WPF程序。我已经创建了两个视图模型。

• 第一个视图模型:显示机场列表。每个机场都可以点击。
• 第二个视图模型:用于显示单击的机场上的详细信息。

我的问题是我无法将活动点击机场传递给viewmodel2。经过一些研究，我认为我必须使用中介模式来在两个视图模型之间进行通信，但我真的不知道如何实现它。

如果你能帮我编写代码，那就太好了。

你会找到并提取我的代码。

VIEWMODEL1：

    public AirportViewModel()
    {
        Airports = new ObservableCollection<AirportModel>(GetData.GetAirportData());//LOAD AIRPORTS FROM XML FILE
        GetAirportIdCommand = new RelayCommand(GetAirportIdExecute, GetAirportIdCanExeucte);
    }

    public static ObservableCollection<AirportModel> Airports { get; set; }

    private AirportModel selectAirport; // AIRPORT CLICK AND NEED TO BE SEND To VIEWMODEL2

    public AirportModel SelectAirport
    {
        get { return selectAirport; }
        set
        {
            if (value != selectAirport)
            { 
                selectAirport = value;
                OnPropertyChanged("SelectAirport");
            }
         }
    }

    public RelayCommand GetAirportIdCommand { get; set; }

    public void GetAirportIdExecute(object parameter)   // COMMAND TO SELECT AN AIRPORT
    {          
        int IdSelectAirport = int.Parse(parameter.ToString());
        SelectAirport = Airports[IdSelectAirport];
        AirportDataWindowViewModel.AirportDataWindowModel.WidthNotam = 500;
    }

    public bool GetAirportIdCanExeucte(object parameter)
    {
        //Bouton toujours actif
        return true;
    }
    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;

        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    #endregion

VIEWMODEL 2

让点击的机场

希望你能帮忙！

提前感谢

西里尔

Answer 1

很抱歉我的回复太晚了。谢谢你的建议和榜样。我用以下代码解决了我的问题。利用IEventAggregator使用棱镜库

我的服务

internal sealed class ApplicationService
{
    private ApplicationService() { }

    private static readonly ApplicationService _instance = new ApplicationService();

    internal static ApplicationService Instance { get { return _instance; } }

    private Prisms.IEventAggregator _eventAggregator;
    internal Prisms.IEventAggregator EventAggregator
    {
        get
        {
            if (_eventAggregator == null)
            {
                _eventAggregator = new Prisms.EventAggregator();
            }


            return _eventAggregator;
        }
    }

然后我的第一个ViewModel，它将发布SelectAirport

public class AirportViewModel :  INotifyPropertyChanged
{
    protected readonly IEventAggregator eventAggregator;


    public AirportViewModel(IEventAggregator EventAggregator)
    {
        //Liste des aéroports a suivre           
        Airports = new ObservableCollection<AirportModel>(GetData.GetAirportData());

        //Clique sur un aéroport
        GetAirportIdCommand = new RelayCommand(GetAirportIdExecute,GetAirportIdCanExeucte);

        #region Telechargement météo

        GetAllWeather GetAllWeather = new GetAllWeather(Airports);

        #endregion


        this.eventAggregator = EventAggregator;

    }
 //Property SelectAirport
    public AirportModel SelectAirport
    {
        get { return selectAirport; }
        set
        {
           selectAirport = value;
          //Publish the property SelectAirport 
          eventAggregator.GetEvent<AirportSelectedEvent> ().Publish(selectAirport);
          OnPropertyChanged("SelectAirport");

        }
    }
}

然后是我的第二个ViewModel，它将接收SelectAirport

public class NotamViewModel  : INotifyPropertyChanged
{
    protected readonly IEventAggregator _eventAggregator;

    public NotamViewModel(IEventAggregator ea)
    {
        _eventAggregator = ea;

        _eventAggregator.GetEvent<AirportSelectedEvent>()
         .Subscribe((_selectAirport) =>
         {
          this.SelectAirport = _selectAirport;


         });
    }
}

最后我的AirportSelectedEvent

public class AirportSelectedEvent : PubSubEvent<AirportModel>
{
}

如果需要的话我希望它能帮到你。

关于WPF的许多其他问题，我们很快就会见到您

西里尔