内核出现InvalidCastException.获取<；键入>；

我有一个WPF应用程序，它可能使用命令行参数启动，也可能不使用命令行args启动。我过去在App.xaml代码后面的OnStartup(StartupEventArgs e)方法中有我的合成根，但这会导致应用程序关闭问题，所以我把App.xaml变成了一个"页面"（而不是"应用程序定义"），并编写了我自己的Program类，其中包含我自己的应用程序入口点，这将成为我的新合成根位置。

自从那次更改以来，我一直无法启动应用程序，Ninject似乎无法解析应用程序的主要对象（或者它可能是它的依赖项之一？）。

这个异常让我浪费了很多时间，堆栈跟踪都是Ninject内部的，我不知道在我的代码中该修复什么，我绑定导致这个异常的类型的方式最近没有改变：

at DynamicInjector54d92ac63a2e47fda5ffbcc19b9942a9(Object[] )
at Ninject.Activation.Providers.StandardProvider.Create(IContext context)
at Ninject.Activation.Context.Resolve()
at Ninject.KernelBase.<>c__DisplayClass10.<Resolve>b__c(IBinding binding)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source)
at Ninject.Planning.Targets.Target`1.GetValue(Type service, IContext parent)
at Ninject.Planning.Targets.Target`1.ResolveWithin(IContext parent)
at Ninject.Activation.Providers.StandardProvider.GetValue(IContext context, ITarget target)
at Ninject.Activation.Providers.StandardProvider.<>c__DisplayClass4.<Create>b__2(ITarget target)
at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at Ninject.Activation.Providers.StandardProvider.Create(IContext context)
at Ninject.Activation.Context.Resolve()
at Ninject.KernelBase.<>c__DisplayClass10.<Resolve>b__c(IBinding binding)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source)
at Ninject.Planning.Targets.Target`1.GetValue(Type service, IContext parent)
at Ninject.Planning.Targets.Target`1.ResolveWithin(IContext parent)
at Ninject.Activation.Providers.StandardProvider.GetValue(IContext context, ITarget target)
at Ninject.Activation.Providers.StandardProvider.<>c__DisplayClass4.<Create>b__2(ITarget target)
at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at Ninject.Activation.Providers.StandardProvider.Create(IContext context)
at Ninject.Activation.Context.Resolve()
at Ninject.KernelBase.<>c__DisplayClass10.<Resolve>b__c(IBinding binding)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source)
at Ninject.Planning.Targets.Target`1.GetValue(Type service, IContext parent)
at Ninject.Planning.Targets.Target`1.ResolveWithin(IContext parent)
at Ninject.Activation.Providers.StandardProvider.GetValue(IContext context, ITarget target)
at Ninject.Activation.Providers.StandardProvider.<>c__DisplayClass4.<Create>b__2(ITarget target)
at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at Ninject.Activation.Providers.StandardProvider.Create(IContext context)
at Ninject.Activation.Context.Resolve()
at Ninject.KernelBase.<>c__DisplayClass10.<Resolve>b__c(IBinding binding)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.<CastIterator>d__b1`1.MoveNext()
at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source)
at Ninject.ResolutionExtensions.Get[T](IResolutionRoot root, IParameter[] parameters)
at MyProgram.Program.Main(String[] args) in C:'Dev'MyProject'MyProject.WinPresentation'Program.cs:ligne 40
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()

以下是Main方法/应用程序入口点：

[STAThread]
public static void Main(string[] args)
{
    var module = new MyAppNinjectModule(args);
    var kernel = new StandardKernel(module);
    var argsHelper = module.CommandLineArgs;
    var logProvider = kernel.Get<ILogProvider>();
    var logger = logProvider.GetLogger(typeof(Program).Name);
    if (argsHelper.LoggingDisabledArgument.IsSpecified()) logProvider.DisableLogging();
    logger.Info(log.LogAppStart);
    var installer = kernel.Get<IInstaller>(); // >>> InvalidCastException here
    if (argsHelper.QuietInterfaceArgument.IsSpecified())
    {
        // running with -quiet command-line switch: just execute and exit.
        installer.Execute();
    }
    else
    {
        // instantiate a new App object (WPF), and run it.
        // installer.Execute() may or may not be executed, depending on user actions.
        var app = new App(installer);
        app.Run();
    }
}

根据提供的命令行参数，NinjectModule将IInstaller绑定到这样或那样的实现（例如，指定了QuietInterfaceArgument时为SilentInstaller，未指定时为ManualInstaller，等等）

通常，Ninject会给非常有用和详细的异常消息——当它是ActivationException时，生命是美好的。但这个InvalidCastException让我一无所知，我不是执行无效强制转换的人，我甚至不知道涉及到什么类型。我只知道我可能写了一些Ninject不喜欢的代码，也许这与我将IInstaller绑定到其实现的方式有关，但如果我注释掉NinjectModule的"分支"部分以强制绑定我想要的特定实现（ManualInstaller），它仍然无法使用此InvalidCastException。

实现的构造函数：

public ManualInstaller(IView<MainWindowViewModel> view, 
                       IProcessHelper processHelper,
                       ISettingsHelper settingsHelper,
                       ILogProvider logProvider,
                       ISetupBootstrapper installer,
                       bool notifySuccess)
    : base(notifySuccess, processHelper, settingsHelper, logProvider, installer)

相应的绑定代码（其他依赖项已经绑定，没有ActivationException，所以不确定这与我的问题有多相关）：

var msg = string.Empty;
if (CommandLineArgs.CompletionMessageArgument.IsSpecified()) 
    msg = CommandLineArgs.CompletionMessageArgument.ParameterValue();
Bind<MainWindowViewModel>().ToSelf().WithConstructorArgument("completionMessage", msg);
Bind<IView<MainWindowViewModel>>().To<MainWindow>();
Bind<IInstaller>().To<ManualInstaller>()
                  .WithConstructorArgument("notifySuccess", notifySuccess);

如果还需要其他东西来了解发生了什么，请毫不犹豫地告诉我…

编辑

单独解决安装程序的依赖关系会产生更多信息：

// resolve installer dependencies:
var view = kernel.Get<IView<MainWindowViewModel>>(); // >>> InvalidCastException here
var processHelper = kernel.Get<IProcessHelper>();
var settingsHelper = kernel.Get<ISettingsHelper>();
var bootstrapper = kernel.Get<ISetupBootstrapper>();
var installer = new ManualInstaller(view, processHelper, settingsHelper, logProvider, bootstrapper, true);

因此，我至少可以将其缩小到我试图解决的类型的一个特定依赖项：问题要么是View，要么是它唯一的依赖项ViewModel。所以我做了这个：

// resolve ViewModel dependencies:
var processHelper = kernel.Get<IProcessHelper>(); // >>> InvalidCastException here
var settingsHelper = kernel.Get<ISettingsHelper>();
var messenger = kernel.Get<INetworkMessenger>();
var factory = kernel.Get<IBuildServerFactory>();
var dialogs = kernel.Get<ICommonDialogs>();

因此，显然是IProcessHelper实现有问题——再次：

// resolve ProcessHelper dependencies:
var processWrapper = kernel.Get<IProcessWrapper>();
var wmiWrapper = kernel.Get<IWindowsManagementInstrumentationWrapper>();
var helper = new ProcessHelper(processWrapper, wmiWrapper, logProvider, 300);

现在我再也拿不到InvalidCastException了。

以下是有问题的类的构造函数和字段：

private readonly ILogProvider _logProvider;
private readonly IProcessWrapper _process;
private readonly IWindowsManagementInstrumentationWrapper _wmi;
public int TimeoutSeconds { get; private set; }
public ProcessHelper(IProcessWrapper process, 
                     IWindowsManagementInstrumentationWrapper wmiWrapper, 
                     ILogProvider logProvider, 
                     int timeout)
{
    _logProvider = logProvider;
    _process = process;
    _wmi = wmiWrapper;
    TimeoutSeconds = timeout;
}

以及NinjectModule如何绑定它：

Bind<IProcessHelper>().To<ProcessHelper>()
                      .WithConstructorArgument("timeout", Properties.Settings.Default.ProcessTimeoutSeconds);

**重新编辑**

在@jure评论的帮助下，我发现Properties.Settings.Default中ProcessTimeoutSeconds的类型实际上被设置为string，而它显然想要int。加油！