VS2015发布多层.NET Framework解决方案后生产环境遇Error 500

问题背景 #

多层.NET Framework解决方案结构：

• BusinessEntity层：包含DTO子层（如BeMonitorRequest.cs）
• Web层：包含Controllers子层（如MonitorController.cs）

使用VS2015发布功能部署到生产环境后，访问api/monitor/getMonitorCasesByFilter接口出现500错误，本地运行正常。错误核心：无法创建MonitorController实例，提示该类型无默认构造函数。

相关代码片段 #

1. MonitorController.cs #

[RoutePrefix("api/monitor")]
public class MonitorController : BaseController
{
  private readonly ISelector iSelector;
  private readonly IMonitorCase iMonitorCase;
  private readonly ITimeConverter iTimeConverter;

  public MonitorController(IMonitorCase iMonitorCase, ISelector iSelector, ITimeConverter iTimeConverter)
  {
    this.iMonitorCase = iMonitorCase;
    this.iSelector = iSelector;
    this.iTimeConverter = iTimeConverter;
  }

  [HttpGet]
  [Route("getMonitorCasesByFilter")]
  public IHttpActionResult CasesByFilter([FromUri] BeMonitorRequest request)
  {
    request.ProjectId = this.GetProject();
    request.UserName = this.GetUserName();
    List<BeMonitorCase> cases = this.iMonitorCase.GetMonitorCasesMainByFilter(request);
    return Ok(cases);
  }
}

2. BeMonitorRequest.cs #

using MyProject.BusinessEntity.DTO;

namespace MyProject.BusinessEntity.DTO
{
  public class BeMonitorRequest 
  {
    public int    ProjectId        { get; set; }
    public string ProjectDB        { get; set; }
    public string From             { get; set; }
    public string To               { get; set; }
    public string RadNumber        { get; set; }
    public string UserName         { get; set; }
    public string FullName         { get; set; }
    public int    ProcessId        { get; set; }
    public string ProcessName      { get; set; }
    public int    TaskId           { get; set; }
    public string NotificationType { get; set; }
    public int    StepTypeId       { get; set; }
    public int    WiClosed         { get; set; }
    public int    WinClosed        { get; set; }
  }
}

3. Startup.cs #

using Microsoft.Owin;
using Owin;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Web;

[assembly: OwinStartup(typeof(MyProject.Web.Startup))]
namespace MyProject.Web
{
    public partial class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;
            Middleware.Configuration(app);
        }
    }
}

4. Middleware.cs #

using Owin;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace MyProject.Web
{
    public class Middleware
    {
        public static void Configuration(IAppBuilder app)
        {
            var container = Dependency.DependencyConfig.Configure();
            WebApiConfig.ConfigureWebApi(app, container);
        }
    }
}

5. DependencyConfig.cs #

using MyProject.Bl;
using MyProject.Bl.Interfaces;
using MyProject.Dal;
using MyProject.Dal.Interfaces;
using MyProject.Utils;
using MyProject.Utils.Interfaces;
using MyProject.Utils.Proxies;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Web;
using Unity;
 
namespace MyProject.Web.Dependency
{
    internal static class DependencyConfig
    {
        internal static IUnityContainer Configure()
        {
            IUnityContainer container = new UnityContainer();
            var host = ConfigurationManager.AppSettings["Host"];
            var connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
            container.RegisterType<ICacheService, MemoryCacheService>();
            container.RegisterInstance<IConfigProxyService>(new ConfigProxyService(host));
            container.RegisterType<IConfigurationCacheService, ConfigurationCacheService>();
 
            container.RegisterInstance<IDalConnection>(new DalConnection(connectionString, true));
 
            //...
            container.RegisterType<IDalMonitorCase, DalMonitorCase>();
            container.RegisterType<IMonitorCase, MonitorCase>();
            //...
 
            return container;
        }
    }
}

6. WebApiUnityResolver.cs #

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Http.Dependencies;
using Unity;
 
namespace MyProject.Web.Dependency
{
    public class WebApiUnityResolver : IDependencyResolver
    {
        protected IUnityContainer container;
        public WebApiUnityResolver(IUnityContainer container)
        {
            if (container == null)
            {
                throw new NotImplementedException("container");
            }
 
            this.container = container;
        }
        public IDependencyScope BeginScope()
        {
            var child = container.CreateChildContainer();
            return new WebApiUnityResolver(child);
        }
 
        public void Dispose()
        {
            container.Dispose();
        }
 
        public object GetService(Type serviceType)
        {
            try
            {
                return container.Resolve(serviceType);
            }
            catch (ResolutionFailedException e)
            {
                return null;
            }
        }
 
        public IEnumerable<object> GetServices(Type serviceType)
        {
            try
            {
                return container.ResolveAll(serviceType);
            }
            catch (ResolutionFailedException)
            {
                return new List<object>();
            }
        }
    }
}

错误详情 #

{
  "message"         : "An error has occurred.",
  "exceptionMessage": "An error occurred when trying to create a controller of type 'MonitorController'. Make sure that the controller has a parameterless public constructor.",
  "exceptionType"   : "System.InvalidOperationException",
  "stackTrace"      : "
      at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
      at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__15.MoveNext()",
  
  "innerException": {
      "message"         : "An error has occurred.",
      "exceptionMessage": "Type 'MyProject.Web.Controllers.MonitorController' does not have a default constructor",
      "exceptionType"   : "System.ArgumentException",
      "stackTrace"      : "
          at System.Linq.Expressions.Expression.New(Type type)
          at System.Web.Http.Internal.TypeActivator.Create[TBase](Type instanceType)
          at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator)
          at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)"
  }
}

环境信息 #

• 本地OS：Windows 10 Enterprise 22H2（19045.4412）
• 服务器OS：Windows Server 2022 Datacenter 21H2（20348.1906）
• 服务器IIS：10.0.20348.1
• VS2015版本：14.0.25431.01 Update 3
• 目标框架：.NET Framework 4.5.2

已尝试方案 #

• 逐个项目清理重建
• 整个解决方案清理重建

解决方案 #

核心问题分析 #

错误说明Web API默认控制器激活器无法找到MonitorController的默认构造函数，本质是Unity依赖注入解析器未正确注册到Web API管道。虽已创建Unity容器和解析器，但需确认WebApiConfig.ConfigureWebApi方法是否完成解析器的注册。

修复步骤 #

1. 完善WebApiConfig.ConfigureWebApi方法，确保将Unity解析器绑定到Web API：

using System.Web.Http;
using Unity;

namespace MyProject.Web
{
    public static class WebApiConfig
    {
        public static void ConfigureWebApi(IAppBuilder app, IUnityContainer container)
        {
            HttpConfiguration config = new HttpConfiguration();
            
            // 启用属性路由
            config.MapHttpAttributeRoutes();
            
            // 设置Web API依赖解析器为Unity实现
            config.DependencyResolver = new Web.Dependency.WebApiUnityResolver(container);
            
            app.UseWebApi(config);
        }
    }
}

2. 补全依赖项注册：
   当前DependencyConfig中仅注册了IMonitorCase，需补充控制器构造函数中另外两个接口的实现注册：

// 在DependencyConfig.Configure方法中添加
container.RegisterType<ISelector, SelectorImpl>(); // 替换为实际实现类
container.RegisterType<ITimeConverter, TimeConverterImpl>(); // 替换为实际实现类

3. 验证生产环境部署包：

• 确认Unity.dll、Unity.AspNet.WebApi.dll等相关依赖已部署到服务器bin目录
• 检查发布配置是否未勾选“排除未使用的依赖项”，避免Unity组件被误删

内容的提问来源于stack exchange，提问作者momiavive