在WebApi 中使用AutoFac

作者: 肉包子一个一块
来源: 51数据库
2021-08-15

参考文档

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

https://www.cnblogs.com/lenmom/p/8510572.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         /// <summary>
13         /// 获取用户是否存在
14         /// </summary>
15         /// <param name="criteria"></param>
16         /// <returns></returns>
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         /// <summary>
20         /// 获取用户是否存在
21         /// </summary>
22         /// <param name="criteria"></param>
23         /// <returns></returns>
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         /// <summary>
50         /// 从autofac容器获取对象
51         /// </summary>
52         /// <typeparam name="t"></typeparam>
53         /// <returns></returns>
54         public static t getfromfac<t>()
55         {
56             return _container.resolve<t>();
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         /// <summary>
11         /// 获取用户是否存在
12         /// </summary>
13         /// <param name="username"></param>
14         /// <param name="password"></param>
15         /// <returns></returns>
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。