Question

当我尝试返回Sales Data时，我有以下代码返回null。如果我删除了employee的其他构造函数，它就可以工作，所以我相信它是构造函数注入问题。

我该如何处理这种注射？

存储库：位于单独的项目中

public class CompanyRepository : ICompanyRepository, IDisposable
{
    public CompanyRepository()
    {

    }

    private readonly IEmployeeRepository _employeeRepository;
    public CompanyRepository(IEmployeeRepository parameter)
    {
        _employeeRepository = parameter;
    }
    //fails never hits this
    private readonly ISalesRepository _salesRepository;
    public CompanyRepository(ISalesRepository parameter)
    {
        _salesRepository = parameter;
    }

}

MVC 5控制器：

[HttpGet]
public ActionResult Create()
{
    //works
    var a = _CompanyRepository.GetCompanyData();
    //works
    var b = _CompanyRepository.GetEmployeeData();
    //fails
    var c = _CompanyRepository.GetSalesData();

    //return view etc
}

App_Start Unity.Config

public static class UnityConfig
{
    public static void RegisterComponents()
    {
        var container = new UnityContainer();

        // register all your components with the container here
        // it is NOT necessary to register your controllers

        container.RegisterType<ICompanyRepository, CompanyRepository>();
        //this one is failing
        container.RegisterType<ICompanyRepository, CompanyRepository>(new InjectionConstructor(new ResolvedParameter<SalesRepository>()));
        container.RegisterType<ICompanyRepository, CompanyRepository>(new InjectionConstructor(typeof(EmployeeRepository)));


        DependencyResolver.SetResolver(new UnityDependencyResolver(container));

    }
}

我刚刚使用但它无法正常使用

container.RegisterType<ICompanyRepository, CompanyRepository>(new InjectionConstructor(typeof(SalesRepository)));
container.RegisterType<ICompanyRepository, CompanyRepository>(new InjectionConstructor(typeof(EmployeeRepository)));

Answer 1

您应该为您的InjectionConstructor注册命名

container.RegisterType<ICompanyRepository, CompanyRepository>("salesRep", new InjectionConstructor(new ResolvedParameter<SalesRepository>()));

container.RegisterType<ICompanyRepository, CompanyRepository>("employeeRep",new InjectionConstructor(new ResolvedParameter<EmployeeRepository>()));

然后像这样解决

var salesRep = container.Resolve<ICompanyRepository>( "salesRep" );

var employeeRep = container.Resolve<ICompanyRepository>( "employeeRep" );

解决的另一种方法是将构造函数更改为

public CompanyRepository([Dependency("employeeRep")]IEmployeeRepository parameter)

public CompanyRepository([Dependency("salesRep")]ISalesRepository parameter)

然后使用DependencyResolver

MVC 5 Unity构造函数注入失败/返回空

1 个答案: