C# 导入不同项目中的构造函数装饰器

我第一次使用这些装饰器（Export（typeOf）和ImportConstructor）

在mvvm体系结构中，我有一个具有以下构造函数的AppViewModel：

[ImportingConstructor]
        public AppViewModel(IEventAggregator events, 
            PatientsManagerViewModel pmvm, TestManagerViewModel tmvm, 
            MainViewModel mvm)
        {

            patientsManagerVM = pmvm;
            testManagerVM = tmvm;
            mainVM = mvm;            
        }

使用以下增压器：

public class AppBootstrapper : Bootstrapper<IShell>
    {
        private CompositionContainer container;

        public AppBootstrapper()
        {
            Start();
        }

        protected override void Configure()
        {
            container = new CompositionContainer(
                new AggregateCatalog(
                    AssemblySource.Instance.Select(x => new AssemblyCatalog(x)).OfType<ComposablePartCatalog>()
                    )
                );

            var batch = new CompositionBatch();

            batch.AddExportedValue<IWindowManager>(new WindowManager());
            batch.AddExportedValue<IEventAggregator>(new EventAggregator());
            batch.AddExportedValue(container);

            container.Compose(batch);
        }

        protected override object GetInstance(Type serviceType, string key)
        {
            string contract = string.IsNullOrEmpty(key) ? AttributedModelServices.GetContractName(serviceType) : key;
            var exports = container.GetExportedValues<object>(contract);

            if (exports.Any())
                return exports.First();

            throw new Exception(string.Format("Could not locate any instances of contract {0}.", contract));
        }

        protected override IEnumerable<object> GetAllInstances(Type serviceType)
        {
            return container.GetExportedValues<object>(AttributedModelServices.GetContractName(serviceType));
        }

        protected override void BuildUp(object instance)
        {
            container.SatisfyImportsOnce(instance);
        }

        protected override void OnStartup(object sender, StartupEventArgs e)
        {
            DisplayRootViewFor<IShell>();
        }
    }

我想我可以从PatientsManagerViewModel对象调用它

但我认为，由于AppViewModel的构造函数需要PatientManager视图模型，而这个需要UOW，所以我无法在AppViewModel构造函数中创建UOW

所以我想我可以做这个修改：

[Export(typeof(IOtherProjectUOW))]
    public class OtherProjectUOW : IOtherProjectUOW, IDisposable
    {
        [....]

        public OtherProjectUOW()
        {
            CreateDbcontext();

            RepositoryProvider repositoryProvider = new Helper.RepositoryProvider(new RepositoryFactories());
            repositoryProvider.DbContext = DbContext;
            RepositoryProvider = repositoryProvider;
        }

（注：该UOW在另一个项目中）

AppViewModel的修改如下：

[Export (typeof(IShell))]
    public class AppViewModel : Conductor<object>, IShell, IHandle<ChangeViewEvent>
    {
        PatientsManagerViewModel patientsManagerVM;
        TestManagerViewModel testManagerVM;
        MainViewModel mainVM;        

        public static IOtherProjectUOW UOW { get; private set; }

        [ImportingConstructor]
        public AppViewModel(IEventAggregator events, 
            PatientsManagerViewModel pmvm, TestManagerViewModel tmvm, 
            MainViewModel mvm, IKantaUOW kuow)
        {
            patientsManagerVM = pmvm;
            testManagerVM = tmvm;
            mainVM = mvm;

            UOW = kuow;          
        }

[导出（类型化（IShell））]
公共类AppViewModel：导体、IShell、IHandle
{
PatientsManagerViewModel patientsManagerVM；
TestManagerViewModel testManagerVM；
MainViewModelMainVM；
公共静态IOtherProjectUOW{get；私有集；}
[导入构造函数]
公共AppViewModel（IEventAggregator事件，
PatientsManagerViewModel pmvm、TestManagerViewModel tmvm、，
主视图模型mvm，IKantaUOW-kuow）
{
patientsManagerVM=pmvm；
testManagerVM=tmvm；
mainVM=mvm；
UOW=kuow；
}

但是如果我尝试这样做，我会在Bootstrapper类中收到一个错误，它说：

--“找不到contract MainApplication.IShell的任何实例。”--

所以我很肯定进出口系统不起作用

感谢您的帮助

[Export (typeof(IShell))]
    public class AppViewModel : Conductor<object>, IShell, IHandle<ChangeViewEvent>
    {
        PatientsManagerViewModel patientsManagerVM;
        TestManagerViewModel testManagerVM;
        MainViewModel mainVM;        

        public static IOtherProjectUOW UOW { get; private set; }

        [ImportingConstructor]
        public AppViewModel(IEventAggregator events, 
            PatientsManagerViewModel pmvm, TestManagerViewModel tmvm, 
            MainViewModel mvm, IKantaUOW kuow)
        {
            patientsManagerVM = pmvm;
            testManagerVM = tmvm;
            mainVM = mvm;

            UOW = kuow;          
        }