在WebApi 中使用AutoFac

参考文档

https://www.cnblogs.com/htsboke/p/10956807.html

https://www.cnblogs.com/lenmom/p/8510572.html
https://www.cnblogs.com/yaopengfei/p/9479268.html

 

在WebApi项目中使用AutoFac，结构如下：

首先在Api项目当中引用AutoFac包，如下图所示：

 

仓储类：

 1     public interface IUsersRepository
 2     {
 3         int GetUserIsExists(UsersEntity criteria);
 4 
 5     }
 6 
 7 
 8     public class UsersRepository : IUsersRepository
 9     {
10         Logger log = LogManager.GetLogger("UsersRepository");
11 
12         /// 

13         /// 获取用户是否存在
14         /// 
15         /// 
16         /// 
17         public int GetUserIsExists(UsersEntity criteria)
18         {
19             string sql = "。。。。";
20             try
21             {
22                  //查询sql代码，此处省略。。。。             
               }
28             catch (Exception ex)
29             {
30                 log.Fatal(ex, "获取用户是否存在异常：{0}，SQL：{1}", ex.Message, sql);
31                 return 0;
32             }
33         }
34     }

服务类：

 1     //接口   
       public interface IUsersService
 4     {
 5         int GetUserIsExists(UsersEntity criteria);
 6 
 7     }
 8 
10     //实现类
11     public class UsersService : IUsersService
12     {
13         private readonly IUsersRepository _usersrepository;     
14         public UsersService(IUsersRepository usersrepository)    //通过构造函数注入
15         {
16             _usersrepository = usersrepository;
17         }
18 
19         /// 

20         /// 获取用户是否存在
21         /// 
22         /// 
23         /// 
24         public int GetUserIsExists(UsersEntity criteria)
25         {
26             return _usersrepository.GetUserIsExists(criteria);
27         }
28     }

在Api接口项目中创建一个AutoFac工具类：AutofacUtil.cs   

 1     public class AutofacUtil
 2     {
 3         private static IContainer _container;
 4 
 5         public static void ConfigureContainer()
 6         {
 7             #region AutoFac IOC容器
 8 
 9             var builder = new ContainerBuilder();
10 
11             try
12             {
13                 //builder.RegisterControllers(Assembly.GetCallingAssembly());  //注册mvc控制器  需要引用package Autofac.Mvc
14 
15                 //builder.RegisterApiControllers(Assembly.GetExecutingAssembly()).PropertiesAutowired();  //支持Api控制器属性注入
16                 builder.RegisterApiControllers(Assembly.GetCallingAssembly());  //注册所有api控制器  构造函数注入  需要引用package Autofac.WebApi
17 
18                 //注册程序集
19                 #region Service
20                 var assemblysServices = Assembly.Load("WebApi.Service");
21                 builder.RegisterAssemblyTypes(assemblysServices)
22                 .AsImplementedInterfaces()
23                 .InstancePerDependency();
24                 #endregion
25                 
26                 #region Repository
27                 var assemblysRepository = Assembly.Load("WebApi.Repository");
28                 builder.RegisterAssemblyTypes(assemblysRepository)
29                 .AsImplementedInterfaces()
30                 .InstancePerDependency();
31                 #endregion
32 
33                 _container = builder.Build();   //创建依赖注入
34 
35 
36                 //设置MVC依赖注入
37                 //DependencyResolver.SetResolver(new AutofacDependencyResolver(_container));
38 
39                 //设置WebApi依赖注入
40                 GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(_container);
41             }
42             catch (Exception ex)
43             {
44                 throw new Exception(ex.Message + "\n" + ex.InnerException);
45             }
46             #endregion
47         }
48 
49         /// 

50         /// 从Autofac容器获取对象
51         /// 
52         /// 
53         /// 
54         public static T GetFromFac()
55         {
56             return _container.Resolve();
57         }
58 
59     }

在 Global.asax.cs 全局中注册一下：

 1   public class WebApiApplication : System.Web.HttpApplication
 2     {
 3         protected void Application_Start()
 4         {
 5             AreaRegistration.RegisterAllAreas();
 6             GlobalConfiguration.Configure(WebApiConfig.Register);
 7             FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
 8             RouteConfig.RegisterRoutes(RouteTable.Routes);
 9             BundleConfig.RegisterBundles(BundleTable.Bundles);
10 
11             //AutoFac 注册
12             AutofacUtil.ConfigureContainer();
13 
14         }
15     }

最后在接口中使用：

 1     public class UsersController : ApiController
 2     {
 3         private readonly IUsersService _usersService;
 4         public UsersController(IUsersService usersService)    //使用构造函数注入
 5         {
 6             _usersService = usersService;
 7         }
 8 
 9 
10         /// 

11         /// 获取用户是否存在
12         /// 
13         /// 
14         /// 
15         /// 
16         [HttpPost]
17         public IHttpActionResult GetUserIsExists(string username, string password)
18         {
19             //验证是否存在当前用户
20             var obModel = new UsersEntity()
21             {
22                 Username = username,
23                 Password = Encryption.MD5(password)
24             };
25             var getresult = _usersService.GetUserIsExists(obModel);
26 
27             return Json(new { isexists = getresult > 0 });
28         }
29 
30 
31     }

测试结果：

 

最后：如果出现 未将对象引用的实例 的错误，检查一下是否引用相应的dll程序集了。