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[ASP.net教程]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.

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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();     }

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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

<? "1.0 "?> < configuration>  < configSections>   <!-- unity程序集-->   < section name= "unity " type =" Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration" />  </ configSections>  < unity "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();     }
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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:

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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.cnblogs.com/files/janes/DemoCache.zip