Question

我收到以下错误。我正在使用.Net Core Web API。

处理请求时发生未处理的异常。 InvalidOperationException：尝试激活“ xxx.Infrastructure.Repository.TagRepository”时，无法解析类型为“ xxx.Infrastructure.Data.xxxContext”的服务。

Api控制器

namespace xxx.API.Controllers
{
    [Route("api/Default")]
    [ApiController]
    public class DefaultController:ControllerBase
    {
         private ITagRepository _tagRepository;
        public DefaultController(ITagRepository tagRepository)
    {
         _tagRepository = tagRepository;
    }

    [HttpGet]
    public string GetAllUserInfo()
    {
        try
        {
            var Tags = _tagRepository.GetAllTagsByInstanceId("");
            if (Tags == null)
            {
                Tags = new List<TagEntity>();
            }
            return Tags.ToString();
        }
        catch (Exception ex)
        {
            return null;
        }
    }
}

Startup.cs

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc().AddControllersAsServices();
        services.AddSingleton<ModulePermissionHelper>();
        services.AddScoped<ITagRepository, TagRepository>();
        services.AddScoped<ITagModuleRepository, TagModuleRepository>();
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseMvc();
    }
}

ITagRepository

public interface ITagRepository
{
    List<TagEntity> GetAllTagsByInstanceId(string instanceId);
}

Answer 1

基于异常消息和所示的启动，DI容器未意识到为了正确激活所需类型所需的依赖项。

您需要在启动过程中将DbContext及其相关配置注册

public void ConfigureServices(IServiceCollection services) {
    services.AddMvc().AddControllersAsServices();
    services.AddSingleton<ModulePermissionHelper>();
    services.AddScoped<ITagRepository, TagRepository>();
    services.AddScoped<ITagModuleRepository, TagModuleRepository>();

    //..
    services.AddDbContext<xxxContext>(options => ...);
}

文档：Using DbContext with dependency injection

尝试激活“ xxx.Infrastructure.TagRepository”时，无法解析类型为“ xxx.Infrastructure”的服务

1 个答案: