Unity容器使用笔记

1、配置文件
说明：此处有两个容器的节点，用来分别初始化两个容器，可以应对需要注入两个dbContext的情况。
代码：
<configuration>
<configSections>
<section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Unity.Configuration"/>
</configSections>
<unity>
<sectionExtension type="Microsoft.Practices.Unity.InterceptionExtension.Configuration.InterceptionConfigurationExtension, Unity.Interception.Configuration"/>
<containers>
<container name="yydyoaSection">
<extension type="Interception"/>
<register type="Study.Unity.Interface.IDoWork,Study.Unity" mapTo=" Study.Unity.Service.StudentDoWork,Study.Unity">
<interceptor type="InterfaceInterceptor"/>
<interceptionBehavior type="Study.Unity.Aop.ParameterCheckBehavior,Study.Unity"/>
<interceptionBehavior type="Study.Unity.Aop.CachingBehavior,Study.Unity"/>
<interceptionBehavior type="Study.Unity.Aop.ExpessionBehavior,Study.Unity"/>
<interceptionBehavior type="Study.Unity.Aop.LogBeforeBehavior,Study.Unity"/>
</register>
</container>
<container name="managerSection">
<extension type="Interception"/>
<register type="Study.Unity.Interface.IDoWork,Study.Unity" mapTo=" Study.Unity.Service.TeacherDoWork,Study.Unity">
<interceptor type="InterfaceInterceptor"/>
</register>
</container>
</containers>
</unity>
</configuration>

2、初始化容器
说明：创建了一个枚举，用来对应配置文件中的两个节点，然后通过扩展方法获取到枚举值在配置文件中的节点名称，用来分别初始化不同的容器。
代码：
容器的工厂：

  public class DIFactory
    {
        private static readonly object _SyncHelper = new object();
        private static volatile Dictionary<EnContainer, IUnityContainer> _UnityContainerDictionary = new Dictionary<EnContainer, IUnityContainer>();

        public static IUnityContainer GetContainer(EnContainer enContainer)
        {
            if (!_UnityContainerDictionary.ContainsKey(enContainer))
            {
                lock (_SyncHelper)
                {
                    if (!_UnityContainerDictionary.ContainsKey(enContainer))
                    {
                        //配置UnityContainer
                        IUnityContainer container = new UnityContainer();
                        ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
                        fileMap.ExeConfigFilename = Path.Combine(AppDomain.CurrentDomain.BaseDirectory + "CfgFiles\\Unity.Config");
                        Configuration configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
                        UnityConfigurationSection configSection = (UnityConfigurationSection)configuration.GetSection(UnityConfigurationSection.SectionName);
                        string strSection = enContainer.Speccn();
                        configSection.Configure(container, strSection);

                        _UnityContainerDictionary.Add(enContainer, container);
                    }
                }
            }
            return _UnityContainerDictionary[enContainer];
        }
    }

    枚举：

 public enum EnContainer
    {
        [Speccn("yydyoaSection")]
        YYDYOA = 1,
        [Speccn("managerSection")]
        MANAGER = 2
    }

    特性：

     [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
    public class SpeccnAttribute : Attribute
    {
        private string Speccn { get; set; }
        public SpeccnAttribute(string speccn)
        {
            this.Speccn = speccn;
        }
        public string GetSpeccn()
        {
            return this.Speccn;
        }
    }

    扩展方法：   

 public static class EnumExtend
    {
        public static string Speccn(this Enum enContainer)
        {
            Type type = enContainer.GetType();
            FieldInfo field = type.GetField(enContainer.ToString());
            if (field.IsDefined(typeof(SpeccnAttribute), true))
            {
                SpeccnAttribute speccnAttribute = (SpeccnAttribute)field.GetCustomAttribute(typeof(SpeccnAttribute));
                return speccnAttribute.GetSpeccn();
            }
            else
            {
                return enContainer.ToString();
            }
        }
    }

3、接口和实现类的代码
接口：

  public interface IDoWork
    {
        string Show(string arg);
    }

    实现类：

 public class StudentDoWork : IDoWork
    {
        public string Show(string arg)
        {
            Console.WriteLine($"{this.GetType().Name}_DoWork Before");
            Console.WriteLine($"{this.GetType().Name}_DoWork After");
            return nameof(StudentDoWork);
        }
    }

        public class TeacherDoWork : IDoWork
    {
        public string Show(string arg)
        {
            Console.WriteLine($"{this.GetType().Name}_DoWork");
            return nameof(TeacherDoWork);
        }
    }

    4、AOP扩展类的代码：
        参数检查：

          public class ParameterCheckBehavior : IInterceptionBehavior
    {
        public bool WillExecute => true;

        public IEnumerable<Type> GetRequiredInterfaces()
        {
            return Type.EmptyTypes;
        }

        public IMethodReturn Invoke(IMethodInvocation input, GetNextInterceptionBehaviorDelegate getNext)
        {
            Console.WriteLine("ParameterCheckBehavior");
            if (input.Inputs[0].ToString().Length < 10)//可以过滤一下敏感词
            {
                //返回一个异常
                return input.CreateExceptionMethodReturn(new Exception("密码长度不能小于10位"));
            }
            else
            {
                Console.WriteLine("参数检测无误");
                return getNext().Invoke(input, getNext);
            }
        }
    }

    日志：

 public class LogBeforeBehavior : IInterceptionBehavior
    {
        public bool WillExecute => true;

        public IEnumerable<Type> GetRequiredInterfaces()
        {
            return Type.EmptyTypes;
        }

        public IMethodReturn Invoke(IMethodInvocation input, GetNextInterceptionBehaviorDelegate getNext)
        {
            Console.WriteLine("LogBehavior before");
            IMethodReturn method = getNext()(input, getNext);
            Console.WriteLine("LogBehavior after");
            return method;
        }
    }

    异常：

 public class ExpessionBehavior : IInterceptionBehavior
    {
        public bool WillExecute => true;

        public IEnumerable<Type> GetRequiredInterfaces()
        {
            return Type.EmptyTypes;
        }

        public IMethodReturn Invoke(IMethodInvocation input, GetNextInterceptionBehaviorDelegate getNext)
        {
            Console.WriteLine("ExpessionBehavior before");

            IMethodReturn method = getNext()(input, getNext);
            if (method.Exception != null)
                Console.WriteLine($"异常:{method.Exception.Message}");
            Console.WriteLine("ExpessionBehavior after");
            return method;
        }
    }

    缓存：

  public class CachingBehavior : IInterceptionBehavior
    {
        public IEnumerable<Type> GetRequiredInterfaces()
        {
            return Type.EmptyTypes;
        }

        private static Dictionary<string, object> CachingBehaviorDictionary = new Dictionary<string, object>();

        public IMethodReturn Invoke(IMethodInvocation input, GetNextInterceptionBehaviorDelegate getNext)
        {
            string key = $"{input.MethodBase.Name}_{Newtonsoft.Json.JsonConvert.SerializeObject(input.Inputs)}";
            if (CachingBehaviorDictionary.ContainsKey(key))
            {
                return input.CreateMethodReturn(CachingBehaviorDictionary[key]);
            }
            else
            {
                IMethodReturn result = getNext().Invoke(input, getNext);
                if (result.ReturnValue != null)
                {
                    CachingBehaviorDictionary.Add(key, result.ReturnValue);
                    Console.WriteLine("CachingBehavior");
                }
                return result;
            }
        }

        public bool WillExecute
        {
            get { return true; }
        }
    }

    5、测试代码

 static void Main(string[] args)
        {
            IUnityContainer yydyoaContainer = DIFactory.GetContainer(EnContainer.YYDYOA);
            IDoWork doWork = yydyoaContainer.Resolve<IDoWork>();
            doWork.Show("12345678901234");
            yydyoaContainer = DIFactory.GetContainer(EnContainer.MANAGER);
            doWork = yydyoaContainer.Resolve<IDoWork>();
            doWork.Show("123");
            Console.ReadKey();
        }

    6、总结
        AOP扩展的进入顺序是根据配置文件从上到下进入，业务逻辑与拓展逻辑的执行顺序是根据getNext().Invoke(input, getNext)代码的位置决定。