Question

您好我收到此错误：

InvalidOperationException：无法解析类型的服务尝试激活时“RegistrationMVC.Model.OurDbContext” 'RegistrationMVC.Controllers.HomeController'。

我不知道是什么原因引起的，可能是依赖的东西吗？

startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using WebApplicationCore.NetCore.DataAccess;
using WebApplicationCore.NetCore.BusinessLogic;
namespace WebApplicationCore.NetCore
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

    public IConfigurationRoot Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        // Add framework services.
        services.AddMvc();

        services.AddSingleton<IConfigurationRoot>(sp => { return this.Configuration; });
        services.AddScoped<IContactDataAccess, ContactDataAccess>();
        services.AddScoped<IContactBusinessLogic, ContactBusinessLogic>();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseBrowserLink();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseStaticFiles();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
    }
}

HomeController

OurDbContext

Answer 1

某些容器会自动实例化类似OurDbContext的类（只要它可以成功构建），因为它是一个可以构造的类型，而其他容器会在依赖项容器中未定义OurDbContext时抛出异常。所以它可能就像没有注册OurDbContext那样简单，容器就是这样......

InvalidOperationException错误

1 个答案: