Question

我有多对接口并实现了这样的

ICategoryService -> CategoryService
ICategoryTypeService -> CategoryTypeService
IOrderService -> OrderService
ILoggingService -> LoggingService

所有类和接口都在Data.dll中，我这样循环它。

foreach (var type in serviceAssembly.GetTypes())
{
    if (type.Name.Contains("Repository") && !type.IsInterface && !type.IsGenericType)
    {
        Type interfaceImplement = type.GetInterfaces().SingleOrDefault(t => t.IsGenericType == false);

        if (interfaceImplement != null)
        {
            System.Diagnostics.Debug.WriteLine($"{type.Name} is inherited by {interfaceImplement.Name}");
            services.AddTransient(interfaceImplement, type);
        }
    }
}

我收到此错误

InvalidOperationException：尝试激活“ VietWebSite.Web.Areas.WebApi.Administrator.ValuesController”时，无法解析类型为“ VietWebSite.Service.ILoggingService”的服务。

但是如果我将代码更改为这样就可以了：

services.AddTransient<ILoggingService, LoggingService>();
services.AddTransient<ICategoryService, CategoryService>();
services.AddTransient<ICategoryTypeService, CategoryTypeService>();
services.AddTransient<IOrderService, OrderService>();

请帮助。

谢谢

Answer 1

您的操作方式是正确的手动操作方式。我知道内置的并没有一种自动注入依赖项的方法，但是有可用的软件包，例如AutoFac https://autofac.org/。

Answer 2

这是一个工作示例：

使用类和接口创建Data库：

public interface ICategoryService
{
    string Output();
}
public class CategoryService : ICategoryService
{
    public string Output()
    {
        return "CategoryService.Output";
    }
}
public interface ILoggingService
{
    string Output();
}
public class LoggingService : ILoggingService
{
    public string Output()
    {
        return "LoggingService.Output";
    }
}

将Data库参考添加到asp.net核心项目

像

一样配置Startup.cs

var serviceAssembly = Assembly.GetAssembly(typeof(CategoryService));
foreach (var type in serviceAssembly.GetTypes())
{
    if (type.Name.Contains("Service") && !type.IsInterface && !type.IsGenericType)
    {
        Type interfaceImplement = type.GetInterfaces().SingleOrDefault(t => t.IsGenericType == false);

        if (interfaceImplement != null)
        {
            System.Diagnostics.Debug.WriteLine($"{type.Name} is inherited by {interfaceImplement.Name}");
            services.AddTransient(interfaceImplement, type);
        }
    }
}

用例：

public class HomeController : Controller
{
    private readonly ILoggingService _loggingService;
    public HomeController(ILoggingService loggingService)
    {
        _loggingService = loggingService;
    }
    public IActionResult Index()
    {
        var result = _loggingService.Output();
        return View();
    }        
}

更新：

您的问题是由AppDomain.CurrentDomain.GetAssemblies()仅返回已加载的程序集引起的，请尝试以下代码：

//Load Assemblies
//Get All assemblies.
var refAssembyNames = Assembly.GetExecutingAssembly()
    .GetReferencedAssemblies();
//Load referenced assemblies
foreach (var asslembyNames in refAssembyNames)
{
    Assembly.Load(asslembyNames);
}
Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
var myAssemblies = assemblies.Where(assem => assem.GetName().Name.Contains("VietWebSite.Data") || assem.GetName().Name.Equals("VietWebSite.Service"));

如何在netcore2中自动添加依赖项

2 个答案: