我正在尝试建立一个MVC网站，当我尝试运行该应用程序时，我会在终端中收到以下响应：
fail: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware[1]
An unhandled exception has occurred while executing the request.
System.Net.Http.HttpRequestException: Connection refused
---> System.Net.Sockets.SocketException (61): Connection refused
at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken
cancellationToken)
--- End of inner exception stack trace ---
at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean allowHttp2, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.GetHttpConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Extensions.Http.Logging.LoggingHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Extensions.Http.Logging.LoggingScopeHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpClient.FinishSendAsyncBuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
at NorthwindMvc.Controllers.HomeController.Customers(String country) in /Users/steelwind/HardWay/c#and.NET/PracticalApps/NorthwindMvc/Controllers/HomeController.cs:line 139
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.MigrationsEndPointMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware.Invoke(HttpContext httpContext)
at Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware.Invoke(HttpContext httpContext)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
Request finished in 744.0667000000001ms 500 text/html; charset=utf-8
Program.cs看起来像这样：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
namespace NorthwindService
{
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
webBuilder.UseUrls("https://localhost.5001");
});
}
}
Startup.cs看起来像这样：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.IO;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using Microsoft.OpenApi.Models;
using Packt.Shared;
using NorthwindService.Repositories;
using Swashbuckle.AspNetCore.Swagger;
using Swashbuckle.AspNetCore.SwaggerUI;
using static System.Console;
namespace NorthwindService
{
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.AddCors();
string databasePath = Path.Combine("..", "Northwind.db");
services.AddDbContext<Northwind>(options => options.UseSqlite($"Data Source={databasePath}"));
services.AddControllers(options =>
{
WriteLine("Default output formatters:");
foreach(IOutputFormatter formatter in options.OutputFormatters)
{
var mediaFormatter = formatter as OutputFormatter;
if (mediaFormatter == null)
{
WriteLine($" {formatter.GetType().Name}");
}
else // OutputFormatter class has SupportedMediaType
{
WriteLine(" {0}, Media types: {1}",
arg0: mediaFormatter.GetType().Name,
arg1: string.Join(", ", mediaFormatter.SupportedMediaTypes));
}
}
})
.AddXmlDataContractSerializerFormatters()
.AddXmlSerializerFormatters()
.SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
services.AddScoped<ICustomerRepository, CustomerRepository>();
// Register the Swagger generator and define a Swagger document
// for Northwind services
services.AddSwaggerGen(options =>
{
options.SwaggerDoc(name: "v1", info: new OpenApiInfo
{ Title = "Northwind Service API", Version = "v1"});
});
services.AddMvcCore();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();
// after UseRouting and before UseEndPoints
app.UseCors(configurePolicy: options =>
{
options.WithMethods("GET", "POST", "PUT", "DELETE");
options.WithOrigins("https://localhost:5002" // for MVC client
);
});
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
app.UseSwagger();
app.UseSwaggerUI(options =>
{
options.SwaggerEndpoint("/swagger/v1/swagger.json", "Northwind Service API Version 1");
options.SupportedSubmitMethods(new[] {
SubmitMethod.Get, SubmitMethod.Post,
SubmitMethod.Put, SubmitMethod.Delete});
});
}
}
}
控制器文件（称为HomeController.cs）如下：
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using System.Net.Http;
using Newtonsoft.Json;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using NorthwindMvc.Models;
using Packt.Shared;
namespace NorthwindMvc.Controllers
{
public class HomeController : Controller
{
private readonly ILogger<HomeController> _logger;
private Northwind db;
private readonly IHttpClientFactory clientFactory;
public HomeController(
ILogger<HomeController> logger,
Northwind injectedContext,
IHttpClientFactory httpClientFactory)
{
_logger = logger;
db = injectedContext;
clientFactory = httpClientFactory;
}
public async Task<IActionResult> Index()
{
var model = new HomeIndexViewModel
{
VisitorCount = (new Random()).Next(1, 1001),
Categories = await db.Categories.ToListAsync(),
Products = await db.Products.ToListAsync()
};
return View(model); // pass model to view
}
public IActionResult Privacy()
{
return View();
}
[ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
public IActionResult Error()
{
return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
}
public async Task<IActionResult> ProductDetail(int? id)
{
if (!id.HasValue)
{
return NotFound("You must pass a product ID in the route, for example, /Home/ProductDetail/21");
}
var model = await db.Products.SingleOrDefaultAsync(p => p.ProductID == id);
if (model == null)
{
return NotFound($"Product with ID of {id} not found.");
}
return View(model); // pass model to view and then return result
}
public IActionResult ModelBinding()
{
return View(); // the page with a form to submit
}
[HttpPost]
public IActionResult ModelBinding(Thing thing)
{
//return View(thing); // show the model bound thing
var model = new HomeModelBindingViewModel
{
Thing = thing,
HasErrors = !ModelState.IsValid,
ValidationErrors = ModelState.Values
.SelectMany(state => state.Errors)
.Select(error => error.ErrorMessage)
};
return View(model);
}
public IActionResult ProductsThatCostMoreThan(decimal? price)
{
if (!price.HasValue)
{
return NotFound("You must pass a product price in the query string, for example, /Home/ProductsThatCostMoreThan?price=50");
}
IEnumerable<Product> model = db.Products
.Include(p => p.Category)
.Include(p => p.Supplier)
.AsEnumerable() // switch to client-side
.Where(p => p.UnitPrice > price);
if (model.Count() == 0)
{
return NotFound($"No products cost more than {price:C}.");
}
ViewData["MaxPrice"] = price.Value.ToString("C");
return View(model); // pass model to view
}
public async Task<IActionResult> Customers(string country)
{
string uri;
if (string.IsNullOrEmpty(country))
{
ViewData["Title"] = "All Customers Worldwide";
uri = "api/customers/";
}
else
{
ViewData["Title"] = $"Customers in {country}";
uri = $"api/customers/?country={country}";
}
var client = clientFactory.CreateClient(
name: "NorthwindService");
var request = new HttpRequestMessage(
method: HttpMethod.Get, requestUri: uri);
HttpResponseMessage response = await client.SendAsync(request);
string jsonString = await response.Content.ReadAsStringAsync();
IEnumerable<Customer> model = JsonConvert
.DeserializeObject<IEnumerable<Customer>>(jsonString);
return View(model);
}
}
}
我尝试查找解决方案，但尚未找到任何可行的解决方案。
答案 0 :(得分：0)
在Program.cs中，此行：
webBuilder.UseUrls("https://localhost.5001");
必须为
webBuilder.UseUrls("https://localhost:5001");