DI 依赖注入之StructureMap框架

DI  依赖注入之StructureMap框架

一.简叙：

structureMap只是DI框架中的其中之一。

二.安装及使用：

1.懒人方法：

使用MVC5项目时，能够直接在nuget程序包中安装StructureMap.MVC5；（根据本身的mvc版本安装对应的）

使用webapi项目时，能够直接在nuget程序包中安装StructureMap.WebApi2

 public class DefaultRegistry : Registry
    {
        #region Constructors and Destructors

        public DefaultRegistry()
        {
            Scan(
                scan =>
                {
                    scan.TheCallingAssembly();
                    scan.WithDefaultConventions();
                });
            //For<IExample>().Use<Example>();
            For<AWSW.IDAL.IUserDAL>().Use<AWSW.DAL.UserDAL>();
            For<AWSW.IBLL.IUserBLL>().Use<AWSW.BLL.UserBLL>();
        }

        #endregion
    }

2.勤快人方法：（手动须要写几个类）

经过nuget方式安装structureMap框架，版本根据本身的项目须要选择。

（1）建立容器：

 public class IoC
    {
        public static IContainer Initialize()
        {
            return new Container(x =>
            {
                x.AddRegistry<DefaultRegistry>();
            });
        }
    }

（2）注册：

public class DefaultRegistry : Registry
    {
        public DefaultRegistry()
        {
            Scan(x =>
            {
                x.TheCallingAssembly();
                x.WithDefaultConventions();
            });
            For<IUserDAL>().Use<UserDAL>();
            For<IUserBLL>().Use<UserBLL>();
        }
    }

（3）调用：（global.asax文件中调用来初始化容器）

 var container = IoC.Initialize();

【到此步，在没有使用mvc或webapi项目的时候已经完了】

（4）mvc使用

SetResoler参数是实现IDependencyResolver的类，因此咱们写个实现它的类，实现便可

DependencyResolver.SetResolver(new MVCStructureMapDependencyResolver(container));

实现IDependencyResolver接口的类

public class MVCStructureMapDependencyResolver : IDependencyResolver
    {
        IContainer _container;
        public MVCStructureMapDependencyResolver(IContainer container)
        {
            this._container = container;
        }
        public object GetService(Type serviceType)
        {
            try
            {
                return this._container.GetInstance(serviceType);
            }
            catch (Exception)
            {
                return null;
            }
        }

        public IEnumerable<object> GetServices(Type serviceType)
        {
            try
            {
                return this._container.GetAllInstances(serviceType).Cast<object>();
            }
            catch (Exception)
            {
                return null;
            }
        }
    }

 

（5）webapi使用：

DependencyResolver的属性须要一个实现IDependencyResolver接口类，而且IDependencyResolver接口内BeginScope的方法返回值又是个接口IDependencyScope，因而还得去实现它。就有了以下的代码：

GlobalConfiguration.Configuration.DependencyResolver = new WebApiStructureMapDependencyResolver(container);

public class WebApiStructureMapDependencyResolver : WebApiStructureMapDependencyScope, IDependencyResolver
    {
        IContainer container;
        public WebApiStructureMapDependencyResolver(IContainer container) : base(container)
        {
            this.container = container;
        }

        IDependencyScope IDependencyResolver.BeginScope()
        {
            return new WebApiStructureMapDependencyScope(container);
        }
    }

    public class WebApiStructureMapDependencyScope : IDependencyScope
    {
        IContainer container;
        public WebApiStructureMapDependencyScope(IContainer container)
        {
            this.container = container;
        }

        public void Dispose()
        {
            this.container.Dispose();
        }

        public object GetService(Type serviceType)
        {
            try
            {
                return container.GetInstance(serviceType);
            }
            catch (Exception)
            {
                return null;
            }
        }

        public IEnumerable<object> GetServices(Type serviceType)
        {
            try
            {
                return container.GetAllInstances(serviceType).Cast<object>();
            }
            catch (Exception)
            {
                return null;
            }
        }
    }