如何為自托管的MVC4API控制器配置依賴注入

在檢查了關于 SO 的所有類似問題后，我的問題仍然存在，所以我要為此提出一個新問題。

我有一個單元測驗，它參考了另一個專案，該專案包含一個 MVC 4 ApiController，它有一個用于依賴注入的建構式。

public class DataController : ApiController
{
    public DataController(IRepository repository){}    
}

在我的測驗中，我正在使用Microsoft.Extensions.DependencyInjection并具有以下設定：

// Note: this redundant type access is necessary to load controllers from a different assembly,
// see https://stackoverflow.com/a/11758025/1468097
var type = typeof(DataController);

var services = new ServiceCollection().AddSingleton<IRepository>(new ImMemoryRepository());
var httpConfiguration = new HttpConfiguration
{ 
    DependencyResolver = new DependencyResolver(services.BuildServiceProvider()),
    IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always
};
httpConfiguration.Routes.MapHttpRoute("Default", "{controller}/{action}");
httpConfiguration.DependencyResolver = new DependencyResolver(services.BuildServiceProvider());
var httpServer = new HttpServer(httpConfiguration);
var client = new HttpClient(httpServer);
var response = await client.GetAsync("http://whatever/data/getdata?id=000");

我有一個相當簡單的依賴決議器實作作為測驗類中的嵌套私有類：

private class DependencyResolver : IDependencyResolver
{
    private readonly ServiceProvider _serviceProvider;

    public DependencyResolver(ServiceProvider serviceProvider) => _serviceProvider = serviceProvider;

    public void Dispose() => _serviceProvider.Dispose();

    public object GetService(Type serviceType) => _serviceProvider.GetService(serviceType);

    public IEnumerable<object> GetServices(Type serviceType) => _serviceProvider.GetServices(serviceType);

    public IDependencyScope BeginScope() => new Scope(_serviceProvider.CreateScope());

    private class Scope : IDependencyScope
    {
        private readonly IServiceScope _scope;

        public Scope(IServiceScope scope) => _scope = scope;

        public void Dispose() => _scope.Dispose();

        public object GetService(Type serviceType) => _scope.ServiceProvider.GetService(serviceType);

        public IEnumerable<object> GetServices(Type serviceType) => _scope.ServiceProvider.GetServices(serviceType);
    }
}

我從測驗中得到的回應是 500 服務器錯誤說

Type 'Mvc.DataController' does not have a default constructor

似乎我正在做所有其他人在 MVC 4 中為依賴注入所做的事情，即使對于這個癥狀非常相似的問題也是如此。

我在這里遺漏了一些明顯的東西嗎？

更新

我試過NinjectResolver歸結為同樣的問題：

var kernel = new StandardKernel();
kernel.Bind<IRepository>().ToConstant(new InMemoryRepository());
var httpConfiguration = new HttpConfiguration
{
    DependencyResolver = new NinjectResolver(kernel)
};

uj5u.com熱心網友回復：

我想通了。

關鍵是您還需要在依賴項配置中添加要訪問的控制器。

就我而言，我只需要添加：

var services = new ServiceCollection();

// This is what was missing.
services.AddTransient<DataController>();

取自這里（盡管我根本沒有使用 OWIN）：如何將 Microsoft.Extensions.DependencyInjection 添加到 OWIN 自托管 WebApi

另一個使用 Autofac 的例子：

var builder = new ContainerBuilder();

// You need to register the assembly that contains your controller.
builder.RegisterApiControllers(typeof(DataController).Assembly);

取自這里：依賴注入不適用于 Owin 自托管 Web Api 2 和 Autofac

標籤：

上一篇：在索引視圖頁面中顯示插入和更新資料的訊息

下一篇：如何重構此EFCore查詢以添加另一個where條件變數？