游刃于MVC、WCF中的Autofac
为了程序的健壮性、扩展性、可维护性，依赖抽象而不是具体实现类等等，于是我选择了Autofac依赖注入容器 就是这个工厂来降低耦合。之前买东西是自己去超市，现在呢 我需要什么东西，他们给送过来直接拿到了。
本例中将会分享
1.Autofac在Mvc的Controller控制器、Filter过滤器的使用
2.WCF中的使用
3.用Autofac来完成Unit Of Work工作单元模式 即同一个界限上下文内可以共享同一个工作单元实例。这样就可以统一提交，起到事务作用、数据统一性。一个http请求只有一个上下文实例也算是性能优化吧， 在这里只用到工作单元的一些皮毛。
Demo全貌如下
- Autofac.DataModel 采用database first的实体数据模型
- Autofac.Repository 实体泛型的仓储模式 ，也可以简单的理解是数据层
- Autofac.CoreService 业务逻辑处理
- Autofac.UnitOfWork 工作单元统一提交
- Autofac.Controllers 控制器层是从Web层把所有控制器提取出来，这里用到区域Area
- AutoFac.Web 前端采用的是MVVM模式的knockout.js ，还有autofac的配置
- Autofac.ViewModel 视图
其中Repository、UnitOfWork、CoreService几者之间调用接口或对供其他层调用接口。
从nuget获取必要的Autofac程序包 Autofac、Autofac.Configuration、Autofac.Integration.Mvc、Autofac.Integration.Wcf
各个层依赖的是接口而不是具体实现类，Autofac是个工厂可以通过编译的代码和xml配置文件两种方式指定接口、实现类来完成注入实例。
这里用的是xml配置的方式，需要用到Autofac.Configuration程序集。这样做有个明显的好处：文件不需要编译；不会扰乱各层关系。为什么这么说呢？如果用代码来完成，web层就需要其他层的接口和实现类 也就是引用Repository、UnitOfWork、CoreService层，很明显web层只需要引用Autofac.Controllers 就足够了。而通过xml配置文件可以在bin目录下找到具体的程序集如:Autofac.CoreService.dll
Autoface依赖注入在MVC里实现
Global.cs
protected void Application_Start() { //创建IOC容器 AutofacRegistion.BuildMvcContainer(); AutofacRegistion.BuildWcfContainer(); AreaRegistration.RegisterAllAreas(); WebApiConfig.Register(GlobalConfiguration.Configuration); FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters); RouteConfig.RegisterRoutes(RouteTable.Routes); }
/// <summary> /// 依赖注入Controller、FilterAtrribute、WCF /// </summary> public class AutofacRegistion { /// <summary> /// 创建 MVC容器（包含Filter） /// </summary> public static void BuildMvcContainer() { var builder = new ContainerBuilder(); //注册Module方法2 在Web.config中配制方式 builder.RegisterModule(new ConfigurationSettingsReader("autofacMvc")); //加载 *.Controllers 层的控制器,否则无法在其他层控制器构造注入，只能在web层注入 Assembly[] asm = GetAllAssembly("*.Controllers.dll").ToArray(); builder.RegisterAssemblyTypes(asm); //注册仓储 Assembly[] asmRepository = GetAllAssembly("*.Repository.dll").ToArray(); builder.RegisterAssemblyTypes(asmRepository) .Where(t => t.Name.EndsWith("Repository")) .AsImplementedInterfaces();
//注入逻辑层也可以通过配置实现
//Assembly[] asmRepositoryService = GetAllAssembly("*.CoreService.dll").ToArray();
//builder.RegisterAssemblyTypes(asmRepositoryService).AsImplementedInterfaces();
builder.RegisterControllers(Assembly.GetExecutingAssembly()); builder.RegisterModelBinders(Assembly.GetExecutingAssembly()); builder.RegisterModelBinderProvider(); //注册过滤器 builder.RegisterFilterProvider(); builder.RegisterType<OperateAttribute>().PropertiesAutowired(); builder.RegisterControllers(typeof(MvcApplication).Assembly); var container = builder.Build(); DependencyResolver.SetResolver(new AutofacDependencyResolver(container)); } /// <summary> ///创建WCF的容器，不存放Controller、Filter /// </summary> public static void BuildWcfContainer() { var builder = new ContainerBuilder(); builder.RegisterModule(new ConfigurationSettingsReader("autofacWcf")); builder.RegisterModelBinders(Assembly.GetExecutingAssembly()); builder.RegisterModelBinderProvider(); var container = builder.Build(); //WCF IOC容器 AutofacHostFactory.Container = container; //DependencyResolver.SetResolver(new AutofacDependencyResolver(container)); } #region 加载程序集 public static List<Assembly> GetAllAssembly(string dllName) { List<string> pluginpath = FindPlugin(dllName); var list = new List<Assembly>(); foreach (string filename in pluginpath) { try { string asmname = Path.GetFileNameWithoutExtension(filename); if (asmname != string.Empty) { Assembly asm = Assembly.LoadFrom(filename); list.Add(asm); } } catch (Exception ex) { Console.Write(ex.Message); } } return list; } //查找所有插件的路径 private static List<string> FindPlugin(string dllName) { List<string> pluginpath = new List<string>(); string path = AppDomain.CurrentDomain.BaseDirectory; string dir = Path.Combine(path, "bin"); string[] dllList = Directory.GetFiles(dir, dllName); if (dllList.Length > 0) { pluginpath.AddRange(dllList.Select(item => Path.Combine(dir, item.Substring(dir.Length + 1)))); } return pluginpath; } #endregion }
说明：
1 web.config还需要配置 globlal代码中对应的【autofacMvc】和【autofacWcf】节点
2 反射*.Controllers.dll获取 Autofac.Controllers程序集，实现注入
3 反射*.Repository.dll获取 Autofac.Repository程序集 以'Repository'结尾的类的实例注入到它所继承的接口，这个就不需要在xml中配置
4 filter的注入和controller的注入方式不一样
5 MVC和WCF注入实例分别存到两个容器中。这就用到Autofac.Integration.Mvc、Autofac.Integration.Wcf两个程序集。WCF注入的容器中不需要Controller、Filter，就可以把相关的反射和注册去掉了。
web.config
<configSections>
<!-- autofac配置-->
<section name="autofacMvc" type="Autofac.Configuration.SectionHandler, Autofac.Configuration" />
<section name="autofacWcf" type="Autofac.Configuration.SectionHandler, Autofac.Configuration" />
</configSections>
<autofacMvc>
<files>
<file name="configs/CoreService.config" section="autofac" />
</files>
</autofacMvc>
<autofacWcf>
<files>
<!--<file name="configs/IocDAL.config" section="autofac" />-->
</files>
</autofacWcf>
<!--↑↑↑↑autofac配置结束↑↑↑↑-->
在上述webconfig中为了统一管理配置，具体指定接口、实现类、和注入实例的生命周期放到了configs/CoreService.config文件中
CoreService.config
<?xml version="1.0" encoding="utf-8"?> <configuration> <configSections> <section name="autofac" type="Autofac.Configuration.SectionHandler, Autofac.Configuration"/> </configSections> <autofac> <components> <!--DbContext上下文的生命周期为【per-lifetime-scope】即http请求的生命周期 --> <component type="Autofac.DataModel.VehicleCheckDBEntities, Autofac.DataModel" service="System.Data.Entity.DbContext, EntityFramework" instance-scope="per-lifetime-scope"/> <component type="Autofac.UnitOfWork.UnitOfWork, Autofac.UnitOfWork" service="Autofac.UnitOfWork.IUnitOfWork, Autofac.UnitOfWork" /> <component type="Autofac.CoreService.Impl.UserManage, Autofac.CoreService" service="Autofac.CoreService.IUserManage, Autofac.CoreService" /> <component type="Autofac.CoreService.Impl.RoleManage, Autofac.CoreService" service="Autofac.CoreService.IRoleManage, Autofac.CoreService" /> </components> </autofac> </configuration>
说明：
1 component组件配置中type、service配置的是实现类、程序集名称（不是命名空间）、接口、程序集名称。
2 instance-scope 配置的是实例的生命周期。本例中用到两种：一是默认的调用一次创建一次；二是一个http请求会共享一个实例，期间会多次用到，但只有一个实例。这个就是工作单元的核心了。instance-scope="per-lifetime-scope"类型共享DbContext的上下文实例。
参考官网 http://docs.autofac.org/en/latest/configuration/xml.html#additional-config-files
注入方式
MVC、WCF下是通过构造方法注入，Filter过滤器是通过访问器get set注入，下面有具体区别。
Controller和其他层的构造注入
public class HomeController : Controller { private readonly IUserManage _userManage; private IRoleManage _roleManage; public HomeController(IUserManage userManage, IRoleManage roleManage) { _userManage = userManage; _roleManage = roleManage; } }
Filter过滤器的注入取得实例
public class OperateAttribute : ActionFilterAttribute { public IUserManage UserManage { get; set; } public override void OnActionExecuted(ActionExecutedContext filterContext) { //Do Something... var user =UserManage.LoadUser(0); if (user == null) { filterContext.Result = new JsonResult { Data=new{message="不合法操作,未能进入"}, JsonRequestBehavior = JsonRequestBehavior.AllowGet }; } } }
WCF注入
<!-- wcf服务文件 --> <%@ ServiceHost Language="C#" Debug="true" Service="CypApp.VehicleWeb.Services.IAutofacService,CypApp.VehicleWeb" Factory="Autofac.Integration.Wcf.AutofacServiceHostFactory, Autofac.Integration.Wcf" %> //契约的实现类服务 /// <summary> /// Autofac wcf注入 /// </summary> public class AutofacService : IAutofacService { private readonly IInspectorBc _functionBc; //构造函数依赖注入 public AutofacService(IInspectorBc functionBc) { _functionBc = functionBc; } public void DoWork() { _functionBc.GetCompanyIdByInspectorId(0); } } }
/// <summary> /// EntityFramework仓储操作基类 /// </summary> /// <typeparam name="TEntity">动态实体类型</typeparam> public class EFRepositoryBase<TEntity> : IRepository<TEntity> where TEntity : class,new() { public EFRepositoryBase(DbContext context) { Context = context; } public DbContext Context { get; set; } public void Dispose() { if (Context==null)return; Context.Dispose(); Context = null; GC.SuppressFinalize(this); } public IQueryable<TEntity> Entities() { return Context.Set<TEntity>().AsQueryable(); } //Delete、Update等等 }
public sealed class UnitOfWork : IUnitOfWork { /// <summary> /// The DbContext /// </summary> private DbContext _dbContext; /// <summary> /// Initializes a new instance of the UnitOfWork class. /// </summary> /// <param name="context">The object context</param> public UnitOfWork(DbContext context) { _dbContext = context; } /// <summary> /// Saves all pending changes /// </summary> /// <returns>The number of objects in an Added, Modified, or Deleted state</returns> public int Commit() { // Save changes with the default options return _dbContext.SaveChanges(); } /// <summary> /// Disposes the current object /// </summary> public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } /// <summary> /// Disposes all external resources. /// </summary> /// <param name="disposing">The dispose indicator.</param> private void Dispose(bool disposing) { if (disposing) { if (_dbContext != null) { _dbContext.Dispose(); _dbContext = null; } } } }
//业务逻辑处理
public class UserManage : IUserManage { private readonly IUserRepository _userRepository; private readonly IUserRoleRepository _userRoleRepository; private IUnitOfWork _unitOfWork; public UserManage(IUserRepository userRepository, IUserRoleRepository userRoleRepository,IUnitOfWork unitOfWork) { _userRepository = userRepository; _userRoleRepository = userRoleRepository; _unitOfWork = unitOfWork; } /// <summary> /// 添加、修改 User /// </summary> /// <param name="userModel"></param> /// <param name="message"></param> /// <returns></returns> public bool SaveUser(UserModel userModel , out string message) { message = null; var userEntity = new Sys_User { UserName = userModel.UserName, Password = userModel.Password, UserTrueName = userModel.UserTrueName, CreateDate = DateTime.Now, }; //添加用户 if (userModel.Id < 1) { _userRepository.Insert(userEntity); _unitOfWork.Commit(); if (userEntity.Id < 1) { message = "添加用户失败"; return false; } } //修改操作 else { //删除用户角色关系 var userRoleIdArray = _userRoleRepository.Entities() .Where(m => m.UserId == userModel.Id) .Select(s => s.Id).ToList(); foreach (var roleId in userRoleIdArray) { _userRoleRepository.Delete(new Sys_User_Roles {Id = roleId}); } } var userRoles = new List<Sys_User_Roles>(); foreach (var roleId in userModel.Role) { userRoles.Add(new Sys_User_Roles { UserId = userModel.Id, RoleId = roleId }); } //添加用户角色关系 _userRoleRepository.Insert(userRoles); return _unitOfWork.Commit() > 0; }
批量删除、批量添加操作只是映射，并未提交，只有Commit后才会保存数据。各个类拿到的DbContext是同一个实例，因此统一提交整个上下文状态才起到了作用。
仓储和工作单元都有销毁方法， 每次调用仓储类和工作单元类， 都会从IOC容器取到共享实例Dbcontext，当处理完业务后会把这些拿到的Dbcontext实例销毁掉。
共享Demo