Autofac没有用参数击中构造函数

Posted 2023-03-31

【中文标题】Autofac没有用参数击中构造函数

【英文标题】：Autofac not hitting constructor with parameter

【发布时间】：2018-05-02 18:56:22

【问题描述】：

Autofac 的默认值是使用参数最多的构造函数，但它一直在使用无参数的默认构造函数。

消费类：

using AlbumApp.Core.Common.Contracts;
using AlbumApp.Core.Common.UI.Core;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AlbumApp.Admin.ViewModels

  public class MainViewModel : ViewModelBase
  
    private static IServiceFactory _serviceFactory;

    public MainViewModel()  

    public MainViewModel(IServiceFactory serviceFactory)
     _serviceFactory = serviceFactory; 

    private DashboardViewModel _dashboardViewModel = new DashboardViewModel(_serviceFactory);

    public DashboardViewModel DashboardViewModel  get  return _dashboardViewModel;  private set    // = new DashboardViewModel();
  

AutofacLoader：

using AlbumApp.Client.Proxies;
using AlbumApp.Core.Common.Contracts;
using Autofac;
using System.Reflection;

namespace AlbumApp.Admin.Bootstrapper

  public static class AutoFacLoader
  
    public static IContainer Init()  
      var builder = Builder();
      return builder.Build(); 

    public static ContainerBuilder Builder() 
      var builder = new ContainerBuilder();
      builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
        .InNamespace("AlbumApp.Admin.ViewModels").SingleInstance();
      builder.RegisterType<ServiceFactory>().As<IServiceFactory>();

      return builder; 
  

App.xaml.cs

using AlbumApp.Admin.Bootstrapper;
using AlbumApp.Core.Common.Core;
using System.Windows;

namespace AlbumApp.Admin

  /// <summary>
  /// Interaction logic for App.xaml
  /// </summary>
  public partial class App : Application
  
    protected override void OnStartup(StartupEventArgs e)
    
      base.OnStartup(e);

      ObjectBase.Container = AutoFacLoader.Init();

    
  

当我在builder.Build 上设置breakpoint 并检查ComponentRegistry 时，它包含ServiceFactory。

Activator = ServiceFactory (ReflectionActivator), Services = [AlbumApp.Core.Common.Contracts.IServiceFactory], Lifetime = Autofac.Core.Lifetime.CurrentScopeLifetime, Sharing = None, Ownership = OwnedByLifetimeScope

我还在MainViewModel 的两个构造函数上设置了一个断点，并且只命中了默认构造函数，因此_serviceFactory 为空。

如何让 Autofac 注入 ServiceFactory？

在无参数构造函数上调用堆栈：

AlbumApp.Admin.exe!AlbumApp.Admin.ViewModels.MainViewModel.MainViewModel() 第 15 行 C# AlbumApp.Admin.exe!AlbumApp.Admin.MainWindow.MainWindow() 第 30 行 C# [本机到托管转换] [托管到本地转换] mscorlib.dll!System.RuntimeType.CreateInstanceSlow(bool publicOnly, bool skipCheckThis, bool fillCache, ref System.Threading.StackCrawlMark stackMark) 未知 mscorlib.dll!System.Activator.CreateInstance(System.Type type, bool nonPublic) 未知 mscorlib.dll!System.RuntimeType.CreateInstanceImpl(System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfoculture, object[] activationAttributes, ref System.Threading.StackCrawlMark stackMark) 未知 mscorlib.dll!System.Activator.CreateInstance(System.Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfoculture, object[] activationAttributes) 未知 mscorlib.dll!System.Activator.CreateInstance(System.Type type, object[] args) 未知 System.Xaml.dll!System.Xaml.Schema.SafeReflectionInvoker.CreateInstanceCritical(System.Type type, object[] arguments) 未知 System.Xaml.dll!System.Xaml.Schema.SafeReflectionInvoker.CreateInstance(System.Type type, object[] arguments) 未知 System.Xaml.dll!System.Xaml.Schema.XamlTypeInvoker.CreateInstanceWithActivator(System.Type type, object[] arguments) 未知 System.Xaml.dll!System.Xaml.Schema.XamlTypeInvoker.CreateInstance(object[] arguments) 未知 System.Xaml.dll!MS.Internal.Xaml.Runtime.ClrObjectRuntime.CreateInstanceWithCtor(System.Xaml.XamlType xamlType, object[] args) 未知 System.Xaml.dll!MS.Internal.Xaml.Runtime.ClrObjectRuntime.CreateInstance(System.Xaml.XamlType xamlType, object[] args) 未知 System.Xaml.dll!MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.CreateInstance(System.Xaml.XamlType xamlType, object[] args) 未知 System.Xaml.dll!System.Xaml.XamlObjectWriter.Logic_CreateAndAssignToParentStart(MS.Internal.Xaml.Context.ObjectWriterContext ctx) 未知 System.Xaml.dll!System.Xaml.XamlObjectWriter.WriteStartMember（System.Xaml.XamlMember 属性）未知 System.Xaml.dll!System.Xaml.XamlWriter.WriteNode（System.Xaml.XamlReader 阅读器）未知 PresentationFramework.dll!System.Windows.Markup.WpfXamlLoader.TransformNodes(System.Xaml.XamlReader xamlReader, System.Xaml.XamlObjectWriter xamlWriter, bool onlyLoadOneNode, bool skipJournaledProperties, bool shouldPassLineNumberInfo, System.Xaml.IXamlLineInfo xamlLineInfo, System.Xaml.IXamlLineInfoConsumer xamlLineInfoConsumer , MS.Internal.Xaml.Context.XamlContextStack 堆栈, System.Windows.Markup.IStyleConnector styleConnector) 未知 PresentationFramework.dll!System.Windows.Markup.WpfXamlLoader.Load(System.Xaml.XamlReader xamlReader, System.Xaml.IXamlObjectWriterFactory writerFactory, bool skipJournaledProperties, object rootObject, System.Xaml.XamlObjectWriterSettings settings, System.Uri baseUri) 未知 PresentationFramework.dll!System.Windows.Markup.WpfXamlLoader.LoadBaml(System.Xaml.XamlReader xamlReader, bool skipJournaledProperties, object rootObject, System.Xaml.Permissions.XamlAccessLevel accessLevel, System.Uri baseUri) 未知 PresentationFramework.dll!System.Windows.Markup.XamlReader.LoadBaml(System.IO.Stream stream, System.Windows.Markup.ParserContext parserContext, object parent, bool closeStream) 未知 PresentationFramework.dll!System.Windows.Application.LoadBamlStreamWithSyncInfo（System.IO.Stream 流，System.Windows.Markup.ParserContext pc）未知 PresentationFramework.dll!System.Windows.Application.LoadComponent(System.Uri resourceLocator, bool bSkipJournaledProperties) 未知 PresentationFramework.dll!System.Windows.Application.DoStartup() 未知 PresentationFramework.dll!System.Windows.Application..ctor.AnonymousMethod__1_0（对象未使用）未知 WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.InternalRealCall（System.Delegate 回调，对象 args，int numArgs）未知 WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(object source, System.Delegate callback, object args, int numArgs, System.Delegate catchHandler) 未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.WrappedInvoke（System.Delegate 回调，对象 args，int numArgs，System.Delegate catchHandler）未知 WindowsBase.dll!System.Windows.Threading.DispatcherOperation.InvokeImpl() 未知 WindowsBase.dll!System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext（对象状态）未知 mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback 回调, 对象状态, bool preserveSyncCtx) 未知 mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback 回调, 对象状态, bool preserveSyncCtx) 未知 mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback 回调, 对象状态) 未知 WindowsBase.dll!MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext executionContext, System.Threading.ContextCallback callback, object state) 未知 WindowsBase.dll!System.Windows.Threading.DispatcherOperation.Invoke() 未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.ProcessQueue() 未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.WndProcHook（System.IntPtr hwnd，int msg，System.IntPtr wParam，System.IntPtr lParam，ref bool 处理）未知 WindowsBase.dll!MS.Win32.HwndWrapper.WndProc（System.IntPtr hwnd，int msg，System.IntPtr wParam，System.IntPtr lParam，ref bool 处理）未知 WindowsBase.dll!MS.Win32.HwndSubclass.DispatcherCallbackOperation(object o) 未知 WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.InternalRealCall（System.Delegate 回调，对象 args，int numArgs）未知 WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(object source, System.Delegate callback, object args, int numArgs, System.Delegate catchHandler) 未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.WrappedInvoke（System.Delegate 回调，对象 args，int numArgs，System.Delegate catchHandler）未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.LegacyInvokeImpl（System.Windows.Threading.DispatcherPriority 优先级，System.TimeSpan 超时，System.Delegate 方法，对象参数，int numArgs）未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.Invoke（System.Windows.Threading.DispatcherPriority 优先级，System.Delegate 方法，对象 arg）未知 WindowsBase.dll!MS.Win32.HwndSubclass.SubclassWndProc(System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam) 未知 [本机到托管转换] [托管到本地转换] WindowsBase.dll!System.Windows.Threading.Dispatcher.TranslateAndDispatchMessage（参考 System.Windows.Interop.MSG 消息）未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame frame) 未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.PushFrame(System.Windows.Threading.DispatcherFrame 框架) 未知 WindowsBase.dll!System.Windows.Threading.Dispatcher.Run() 未知 PresentationFramework.dll!System.Windows.Application.RunDispatcher（对象忽略）未知 PresentationFramework.dll!System.Windows.Application.RunInternal(System.Windows.Window 窗口) 未知 PresentationFramework.dll!System.Windows.Application.Run(System.Windows.Window 窗口) 未知 PresentationFramework.dll!System.Windows.Application.Run() 未知 AlbumApp.Admin.exe!AlbumApp.Admin.App.Main() 未知 [本机到托管转换] [托管到本地转换] mscorlib.dll!System.AppDomain.nExecuteAssembly（System.Reflection.RuntimeAssembly 程序集，字符串 [] args）未知 mscorlib.dll!System.AppDomain.ExecuteAssembly（字符串 assemblyFile，System.Security.Policy.Evidence assemblySecurity，string[] args）未知 Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() 未知 mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context（对象状态）未知 mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback 回调, 对象状态, bool preserveSyncCtx) 未知 mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback 回调, 对象状态, bool preserveSyncCtx) 未知 mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback 回调, 对象状态) 未知 mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() 未知

【问题讨论】：

你能在构造函数上添加一个断点并发布堆栈跟踪吗？该类型可能没有被 Autofac 初始化。

什么堆栈跟踪？没有抛出错误，因此没有堆栈跟踪。它永远不会使用 IServiceFactory serviceFactory 参数命中构造函数。

我的意思是当无参数构造函数被命中时调用堆栈。

已发布。

你的类不是由 Autofac 而是由 WPF 构建的。您如何将您的AutoFacLoader 链接到您的 WPF 应用程序？我对 WPF 了解不够，但问题似乎就在那里。

【参考方案1】：

ViewModelBase 类包含 AutoFac Container，它被填充到 App.xaml.cs 中。通过从Container 解析它们来初始化ViewModels。

更新 MainViewModel.cs

  public class MainViewModel : ViewModelBase
  
    public MainViewModel()   

    public DashboardViewModel DashboardViewModel 
      get  return Container.Resolve<DashboardViewModel>();     private set   

    public MaintainAlbumsViewModel MaintainAlbumsViewModel 
      get  return Container.Resolve<MaintainAlbumsViewModel>();      private set   

    public OrdersViewModel OrdersViewModel 
      get  return Container.Resolve<OrdersViewModel>();        private set