将 ASP.NET 核心应用程序部署到 Azure 应用服务时出错

Question

下面是错误，

    Application startup exception: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
       at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
       at Microsoft.AspNetCore.Mvc.Internal.DefaultAssemblyPartDiscoveryProvider.CandidateResolver.ComputeClassification(String dependency)
       at Microsoft.AspNetCore.Mvc.Internal.DefaultAssemblyPartDiscoveryProvider.CandidateResolver.ComputeClassification(String dependency)
       at Microsoft.AspNetCore.Mvc.Internal.DefaultAssemblyPartDiscoveryProvider.CandidateResolver.ComputeClassification(String dependency)
       at Microsoft.AspNetCore.Mvc.Internal.DefaultAssemblyPartDiscoveryProvider.CandidateResolver.<GetCandidates>d__4.MoveNext()
       at System.Linq.Enumerable.<SelectManyIterator>d__17`2.MoveNext()
       at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
       at Microsoft.Extensions.DependencyInjection.MvcCoreServiceCollectionExtensions.GetApplicationPartManager(IServiceCollection services)
       at Microsoft.Extensions.DependencyInjection.MvcCoreServiceCollectionExtensions.AddMvcCore(IServiceCollection services)
       at Microsoft.Extensions.DependencyInjection.MvcServiceCollectionExtensions.AddMvc(IServiceCollection services)
       at LeapfrogDataService.Startup.ConfigureServices(IServiceCollection services)
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at Microsoft.AspNetCore.Hosting.ConventionBasedStartup.ConfigureServices(IServiceCollection services)
       at Microsoft.AspNetCore.Hosting.Internal.WebHost.EnsureApplicationServices()
       at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()

我的Program.cs长得像，

    using System.IO;
    using Microsoft.AspNetCore.Hosting;

    namespace LeapfrogDataService
    {
        /// <summary>
        /// 
        /// </summary>
        public class Program
        {
            /// <summary>
            /// 
            /// </summary>
            /// <param name="args"></param>
            public static void Main(string[] args)
            {
                var host = new WebHostBuilder()
                    .UseKestrel()
                    .UseContentRoot(Directory.GetCurrentDirectory())
                    .UseIISIntegration()
                    .UseStartup<Startup>()
                    .Build();

                host.Run();
            }
        }
    }

而且startup.cs看起来像，

using System.IO;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Rewrite;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.PlatformAbstractions;
using Swashbuckle.AspNetCore.Swagger;

namespace LeapfrogDataService
{
    /// <summary>
    /// 
    /// </summary>
    public class Startup
    {
        /// <summary>
        /// 
        /// </summary>
        /// <param name="env"></param>
        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);

            if (env.IsEnvironment("Development"))
            {
                // This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately.
                builder.AddApplicationInsightsSettings(developerMode: true);
            }

            builder.AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        /// <summary>
        /// 
        /// </summary>
        public IConfigurationRoot Configuration { get; }

        /// <summary>
        /// This method gets called by the runtime. Use this method to add services to the container
        /// </summary>
        /// <param name="services"></param>
        public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddApplicationInsightsTelemetry(Configuration);

            services.AddMvc();

            services.Configure<MvcOptions>(options =>
            {
                options.Filters.Add(new RequireHttpsAttribute());
            });

            // Register the Swagger generator, defining one or more Swagger documents
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new Info { Title = "Leapfrog API", Version = "v1" });
                var filePath = Path.Combine(PlatformServices.Default.Application.ApplicationBasePath, "LeapfrogDataService.xml");
                c.IncludeXmlComments(filePath);
            });

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

            app.UseMvc();

            var options = new RewriteOptions()
                .AddRedirectToHttps();

            app.UseRewriter(options);

            // Enable middleware to serve generated Swagger as a JSON endpoint.
            app.UseSwagger();

            // Enable middleware to serve swagger-ui (HTML, JS, CSS etc.), specifying the Swagger JSON endpoint.
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("/swagger/v1/swagger.json", "Leapfrog API V1");
            });
        }
    }
}

有人可以帮忙解决这个错误吗？

Answer 1

解决方法是，

我在 ConfigureServices 方法的 Startup.cs 中添加了以下几行。

// Configuring application part for MVC
var assembly = typeof(Startup).GetTypeInfo().Assembly;
var part = new AssemblyPart(assembly);
services.AddMvc().ConfigureApplicationPartManager(apm => apm.ApplicationParts.Add(part));

并且，还更新了与我的项目关联的每个 NuGet 包，不知道这是否真的有帮助，但我还是做到了。