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