Unity Container 应用示例

一 项目引用Unity

右键项目引用-> 管理Nuget包->搜索unity->安装Unity 和 Unity Interception Extension,如下图所示.

二 创建基础类

我们以商品查询的数据层注入为例.

1.首先创建商品实体Model. 如果商品信息要被序列化,就要为该类添加Serializable特性.

public class PRoduct    {        public int Id { get; set; }        public string Name { get; set; }        public int Price { get; set; }        public override string ToString()        {            return string.Format(" Product id:{0}/r/n Name:{1}/r/n Price:{2}/r/n",Id,Name,Price);        }    }

2.创建数据层接口及其实现类.

public interface iproductDao    {        Product Get(int id);    }

public class ProductDao:IProductDao    {        public Product Get(int id)        {            #warning product info for test            return new Product()            {                Id = id,                Name = "Product"+id,                Price = id*10            };        }    }

3.直接创建实例

其实有了以上内容就可以调用查询商品信息了.

static void Main( string[] args)         { IProductDao productDao= new ProductDao(); Product product = productDao.Get(5); Console.WriteLine(product.ToString()); Console.Read();         }

不过在项目中使用这种方式的话,耦合度比较高.一旦想修改IProductDao的实现方式涉及到的地方就太多了. 使用Unity实现依赖注入可以降低耦合.

三.使用Unity实现依赖注入

1.创建Unity配置文件

<? xml version= "1.0 "?> < configuration>   < configSections>     <!-- unity程序集-->     < section name= "unity " type =" Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration" />   </ configSections>   < unity xmlns= "http://schemas.microsoft.com/practices/2010/unity ">     <!-- 程序集和命名空间 -->     < assembly name= "DemoCache "/>     < namespace name= "DemoCache.Dao "/>     < namespace name= "DemoCache.Dao.Impl "/>     < container name= "Dao ">       <!-- 商品 -->       < register type= "IProductDao " mapTo= "ProductDao "></ register>     </ container>   </ unity> </ configuration>

2.创建UnityContainerManager类

创建UnityContainerManager读取Unity.config配置. 完整代码见附件,重点看一下从Unity.config读取配置信息的方法:

private IUnityContainer LoadUnityConfig()        {            ////根据文件名获取指定config文件            string filePath = AppDomain.CurrentDomain.BaseDirectory + @"Configs/Unity.config";            var fileMap = new ExeConfigurationFileMap { ExeConfigFilename = filePath };            //从config文件中读取配置信息            Configuration configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);            var unitySection = (UnityConfigurationSection)configuration.GetSection("unity");            var container = new UnityContainer();            foreach (var item in unitySection.Containers)            {                container.LoadConfiguration(unitySection, item.Name);            }            return container;        }

3.调用示例

static void Main( string[] args)         { IProductDao productDao = UnityContainerManager .Instance.Resolve<IProductDao >(); Product product = productDao.Get(8); Console.WriteLine(product.ToString()); Console.Read();         }

四 使用Unity Interception实现日志

1.创建ICallHandler接口实现类

新建类LogCallHandler类,实现接口ICallHandler. 每次调用相应方法时会自动将执行时间写入日志.

public class LogCallHandler:ICallHandler    {        public IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext)        {            //计时开始            var stopWatch = new Stopwatch();            stopWatch.Start();            //执行方法            IMethodReturn result = getNext()(input, getNext);            //计时结束            stopWatch.Stop();            //记录日志            var argumentsSb = new StringBuilder(input.MethodBase.Name);            for (var i = 0; i < input.Arguments.Count; i++)            {                argumentsSb.AppendFormat("-{0}:{1}", input.Arguments.ParameterName(i), input.Arguments[i]);            }            LogHelper.LogInfo(string.Format("{2} 方法 {0},执行时间 {1} ms", argumentsSb, stopWatch.ElapsedMilliseconds,Msg));            return result;        }        public int Order { get; set; }        public string Msg { get; set; }    }

2.创建特性

创建特性LogTime,它需要实现HandlerAttribute.

public class LogTimeAttributes:HandlerAttribute    {        public int Order { get; set; }        public string Msg { get; set; }        public override ICallHandler CreateHandler(IUnityContainer container)        {            return new LogCallHandler()            {                Order = Order,                Msg = Msg            };        }    }

3.使用特性

[LogTimeAttributes (Order = 1,Msg = "查询单个商品信息" )]

4.配置Unity.config

配置Unity Interception需要在unity节点下添加:

< sectionExtension 

type =" Microsoft.Practices.Unity.InterceptionExtension.Configuration.InterceptionConfigurationExtension,Microsoft.Practices.Unity.Interception.Configuration ">

</ sectionExtension >

然后在container节点下添加:

< extension type= "Interception " />

最后调整IProductDao的注册节点:

< register type= "IProductDao " mapTo= "ProductDao ">         < interceptor type =" InterfaceInterceptor" />         < policyInjection /> </ register>

调用处不用做调整,结果如下:

5.不使用Unity.config配置文件

其实如果不走Unity.config配置文件,也可以直接在代码中设置.

static void Main(string[] args)        {                    var container = new UnityContainer().AddNewExtension<Interception>().RegisterType<IProductDao, ProductDao>();            container.Configure<Interception>().SetInterceptorFor<IProductDao>(new InterfaceInterceptor());            IProductDao productDao = container.Resolve<IProductDao>();            Product product = productDao.Get(8);            Console.WriteLine(product);            Console.Read();        }

代码: http://files.VEVb.com/files/janes/DemoCache.zip