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