WCF如何使用動態代理精簡代碼架構

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使用Castle.Core.dll實現，核心代碼是使用Castle.DynamicProxy.ProxyGenerator類的CreateInterfaceProxyWithoutTarget方法動態創建代理對象

NuGet上面Castle.Core的下載量1.78億之多

一、重構前的項目代碼

    重構前的項目代碼共7層代碼，其中WCF服務端3層，WCF接口層1層，客戶端3層，共7層

    1.服務端WCF服務層SunCreate.InfoPlatform.Server.Service

    2.服務端數據庫訪問接口層SunCreate.InfoPlatform.Server.Bussiness

    3.服務端數據庫訪問實現層SunCreate.InfoPlatform.Server.Bussiness.Impl

    4.WCF接口層SunCreate.InfoPlatform.Contract

    5.客戶端代理層SunCreate.InfoPlatform.Client.Proxy

    6.客戶端業務接口層SunCreate.InfoPlatform.Client.Bussiness

    7.客戶端業務實現層SunCreate.InfoPlatform.Client.Bussiness.Impl

二、客戶端通過動態代理重構

    1.實現在攔截器中添加Ticket、處理異常、Close對象

    2.客戶端不需要再寫代理層代碼，而使用動態代理層

    3.對於簡單的增刪改查業務功能，也不需要再寫業務接口層和業務實現層，直接調用動態代理；對於復雜的業務功能以及緩存，才需要寫業務接口層和業務實現層

客戶端動態代理工廠類ProxyFactory代碼(該代碼目前寫在客戶端業務實現層)：

using Castle.DynamicProxy;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;

namespace SunCreate.InfoPlatform.Client.Bussiness.Imp
{
 /// <summary>
 /// WCF服務工廠
 /// PF是ProxyFactory的簡寫
 /// </summary>
 public class PF
 {
 /// <summary>
 /// 攔截器緩存
 /// </summary>
 private static ConcurrentDictionary<Type, IInterceptor> _interceptors = new ConcurrentDictionary<Type, IInterceptor>();

 /// <summary>
 /// 代理對象緩存
 /// </summary>
 private static ConcurrentDictionary<Type, object> _objs = new ConcurrentDictionary<Type, object>();

 private static ProxyGenerator _proxyGenerator = new ProxyGenerator();

 /// <summary>
 /// 獲取WCF服務
 /// </summary>
 /// <typeparam name="T">WCF接口</typeparam>
 public static T Get<T>()
 {
  Type interfaceType = typeof(T);

  IInterceptor interceptor = _interceptors.GetOrAdd(interfaceType, type =>
  {
  string serviceName = interfaceType.Name.Substring(1); //服務名稱
  ChannelFactory<T> channelFactory = new ChannelFactory<T>(serviceName);
  return new ProxyInterceptor<T>(channelFactory);
  });

  return (T)_objs.GetOrAdd(interfaceType, type => _proxyGenerator.CreateInterfaceProxyWithoutTarget(interfaceType, interceptor)); //根據接口類型動態創建代理對象，接口沒有實現類
 }
 }
}

客戶端攔截器類ProxyInterceptor<T>代碼(該代碼目前寫在客戶端業務實現層)：

using Castle.DynamicProxy;
using log4net;
using SunCreate.Common.Base;
using SunCreate.InfoPlatform.Client.Bussiness;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Text;
using System.Threading.Tasks;

namespace SunCreate.InfoPlatform.Client.Bussiness.Imp
{
 /// <summary>
 /// 攔截器
 /// </summary>
 /// <typeparam name="T">接口</typeparam>
 public class ProxyInterceptor<T> : IInterceptor
 {
 private static ILog _log = LogManager.GetLogger(typeof(ProxyInterceptor<T>));

 private ChannelFactory<T> _channelFactory;

 public ProxyInterceptor(ChannelFactory<T> channelFactory)
 {
  _channelFactory = channelFactory;
 }

 /// <summary>
 /// 攔截方法
 /// </summary>
 public void Intercept(IInvocation invocation)
 {
  //準備參數
  ParameterInfo[] parameterInfoArr = invocation.Method.GetParameters();
  object[] valArr = new object[parameterInfoArr.Length];
  for (int i = 0; i < parameterInfoArr.Length; i++)
  {
  valArr[i] = invocation.GetArgumentValue(i);
  }

  //執行方法
  T server = _channelFactory.CreateChannel();
  using (OperationContextScope scope = new OperationContextScope(server as IContextChannel))
  {
  try
  {
   HI.Get<ISecurityBussiness>().AddTicket();

   invocation.ReturnValue = invocation.Method.Invoke(server, valArr);

   var value = HI.Get<ISecurityBussiness>().GetValue();
   ((IChannel)server).Close();
  }
  catch (Exception ex)
  {
   _log.Error("ProxyInterceptor " + typeof(T).Name + " " + invocation.Method.Name + " 異常", ex);
   ((IChannel)server).Abort();
  }
  }

  //out和ref參數處理
  for (int i = 0; i < parameterInfoArr.Length; i++)
  {
  ParameterInfo paramInfo = parameterInfoArr[i];
  if (paramInfo.IsOut || paramInfo.ParameterType.IsByRef)
  {
   invocation.SetArgumentValue(i, valArr[i]);
  }
  }
 }
 }
}

如何使用：

List<EscortTask> list = PF.Get<IBussDataService>().GetEscortTaskList();

這裡不用再寫try catch，異常在攔截器中處理

三、WCF服務端通過動態代理，在攔截器中校驗Ticket、處理異常

服務端動態代理工廠類ProxyFactory代碼(代碼中保存動態代理dll不是必需的)：

using Autofac;
using Castle.DynamicProxy;
using Castle.DynamicProxy.Generators;
using SunCreate.Common.Base;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.Text;
using System.Threading.Tasks;

namespace SunCreate.InfoPlatform.WinService
{
 /// <summary>
 /// 動態代理工廠
 /// </summary>
 public class ProxyFactory
 {
 /// <summary>
 /// 攔截器緩存
 /// </summary>
 private static ConcurrentDictionary<Type, IInterceptor> _interceptors = new ConcurrentDictionary<Type, IInterceptor>();

 /// <summary>
 /// 代理對象緩存
 /// </summary>
 private static ConcurrentDictionary<Type, object> _objs = new ConcurrentDictionary<Type, object>();

 private static ProxyGenerator _proxyGenerator;

 private static ModuleScope _scope;

 private static ProxyGenerationOptions _options;

 static ProxyFactory()
 {
  AttributesToAvoidReplicating.Add(typeof(ServiceContractAttribute)); //動態代理類不繼承接口的ServiceContractAttribute

  String path = AppDomain.CurrentDomain.BaseDirectory;

  _scope = new ModuleScope(true, false,
  ModuleScope.DEFAULT_ASSEMBLY_NAME,
  Path.Combine(path, ModuleScope.DEFAULT_FILE_NAME),
  "MyDynamicProxy.Proxies",
  Path.Combine(path, "MyDymamicProxy.Proxies.dll"));
  var builder = new DefaultProxyBuilder(_scope);

  _options = new ProxyGenerationOptions();

  //給動態代理類添加AspNetCompatibilityRequirementsAttribute屬性
  PropertyInfo proInfoAspNet = typeof(AspNetCompatibilityRequirementsAttribute).GetProperty("RequirementsMode");
  CustomAttributeInfo customAttributeInfo = new CustomAttributeInfo(typeof(AspNetCompatibilityRequirementsAttribute).GetConstructor(new Type[0]), new object[0], new PropertyInfo[] { proInfoAspNet }, new object[] { AspNetCompatibilityRequirementsMode.Allowed });
  _options.AdditionalAttributes.Add(customAttributeInfo);

  //給動態代理類添加ServiceBehaviorAttribute屬性
  PropertyInfo proInfoInstanceContextMode = typeof(ServiceBehaviorAttribute).GetProperty("InstanceContextMode");
  PropertyInfo proInfoConcurrencyMode = typeof(ServiceBehaviorAttribute).GetProperty("ConcurrencyMode");
  customAttributeInfo = new CustomAttributeInfo(typeof(ServiceBehaviorAttribute).GetConstructor(new Type[0]), new object[0], new PropertyInfo[] { proInfoInstanceContextMode, proInfoConcurrencyMode }, new object[] { InstanceContextMode.Single, ConcurrencyMode.Multiple });
  _options.AdditionalAttributes.Add(customAttributeInfo);

  _proxyGenerator = new ProxyGenerator(builder);
 }

 /// <summary>
 /// 動態創建代理
 /// </summary>
 public static object CreateProxy(Type contractInterfaceType, Type impInterfaceType)
 {
  IInterceptor interceptor = _interceptors.GetOrAdd(impInterfaceType, type =>
  {
  object _impl = HI.Provider.GetService(impInterfaceType);
  return new ProxyInterceptor(_impl);
  });

  return _objs.GetOrAdd(contractInterfaceType, type => _proxyGenerator.CreateInterfaceProxyWithoutTarget(contractInterfaceType, _options, interceptor)); //根據接口類型動態創建代理對象，接口沒有實現類
 }

 /// <summary>
 /// 保存動態代理dll
 /// </summary>
 public static void Save()
 {
  string filePath = Path.Combine(_scope.WeakNamedModuleDirectory, _scope.WeakNamedModuleName);
  if (File.Exists(filePath))
  {
  File.Delete(filePath);
  }
  _scope.SaveAssembly(false);
 }
 }
}

說明：object _impl = HI.Provider.GetService(impInterfaceType); 這句代碼用於創建數據庫訪問層對象，HI是項目中的一個工具類，類似Autofac框架的功能

服務端攔截器類ProxyInterceptor<T>代碼：

using Castle.DynamicProxy;
using log4net;
using SunCreate.Common.Base;
using SunCreate.InfoPlatform.Server.Bussiness;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Text;
using System.Threading.Tasks;

namespace SunCreate.InfoPlatform.WinService
{
 /// <summary>
 /// 攔截器
 /// </summary>
 public class ProxyInterceptor : IInterceptor
 {
 private static ILog _log = LogManager.GetLogger(typeof(ProxyInterceptor));

 private object _impl;

 public ProxyInterceptor(object impl)
 {
  _impl = impl;
 }

 /// <summary>
 /// 攔截方法
 /// </summary>
 public void Intercept(IInvocation invocation)
 {
  //準備參數
  ParameterInfo[] parameterInfoArr = invocation.Method.GetParameters();
  object[] valArr = new object[parameterInfoArr.Length];
  for (int i = 0; i < parameterInfoArr.Length; i++)
  {
  valArr[i] = invocation.GetArgumentValue(i);
  }

  //執行方法
  try
  {
  if (HI.Get<ISecurityImp>().CheckTicket())
  {
   Type implType = _impl.GetType();
   MethodInfo methodInfo = implType.GetMethod(invocation.Method.Name);
   invocation.ReturnValue = methodInfo.Invoke(_impl, valArr);
  }
  }
  catch (Exception ex)
  {
  _log.Error("ProxyInterceptor " + invocation.TargetType.Name + " " + invocation.Method.Name + " 異常", ex);
  }

  //out和ref參數處理
  for (int i = 0; i < parameterInfoArr.Length; i++)
  {
  ParameterInfo paramInfo = parameterInfoArr[i];
  if (paramInfo.IsOut || paramInfo.ParameterType.IsByRef)
  {
   invocation.SetArgumentValue(i, valArr[i]);
  }
  }
 }
 }
}

服務端WCF的ServiceHost工廠類：

using Spring.ServiceModel.Activation;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;

namespace SunCreate.InfoPlatform.WinService
{
 public class MyServiceHostFactory : ServiceHostFactory
 {
 public MyServiceHostFactory() { }

 public override ServiceHostBase CreateServiceHost(string reference, Uri[] baseAddresses)
 {
  Assembly contractAssembly = Assembly.GetAssembly(typeof(SunCreate.InfoPlatform.Contract.IBaseDataService));
  Assembly impAssembly = Assembly.GetAssembly(typeof(SunCreate.InfoPlatform.Server.Bussiness.IBaseDataImp));
  Type contractInterfaceType = contractAssembly.GetType("SunCreate.InfoPlatform.Contract.I" + reference);
  Type impInterfaceType = impAssembly.GetType("SunCreate.InfoPlatform.Server.Bussiness.I" + reference.Replace("Service", "Imp"));
  if (contractInterfaceType != null && impInterfaceType != null)
  {
  var proxy = ProxyFactory.CreateProxy(contractInterfaceType, impInterfaceType);
  ServiceHostBase host = new ServiceHost(proxy, baseAddresses);
  return host;
  }
  else
  {
  return null;
  }
 }
 }
}

svc文件配置ServiceHost工廠類：

<%@ ServiceHost Language="C#" Debug="true" Service="BaseDataService" Factory="SunCreate.InfoPlatform.WinService.MyServiceHostFactory" %>

如何使用自定義的ServiceHost工廠類啟動WCF服務，下面是部分代碼：

MyServiceHostFactory factory = new MyServiceHostFactory();
List<ServiceHostBase> hostList = new List<ServiceHostBase>();
foreach (var oFile in dirInfo.GetFiles())
{
 try
 {
 string strSerName = oFile.Name.Replace(oFile.Extension, "");
 string strUrl = string.Format(m_strBaseUrl, m_serverPort, oFile.Name);
 var host = factory.CreateServiceHost(strSerName, new Uri[] { new Uri(strUrl) });
 if (host != null)
 {
  hostList.Add(host);
 }
 }
 catch (Exception ex)
 {
 Console.WriteLine("出現異常：" + ex.Message);
 m_log.ErrorFormat(ex.Message + ex.StackTrace);
 }
}
ProxyFactory.Save();
foreach (var host in hostList)
{
 try
 {
 foreach (var endpoint in host.Description.Endpoints)
 {
  endpoint.EndpointBehaviors.Add(new MyEndPointBehavior()); //用於添加消息攔截器、全局異常攔截器
 }
 host.Open();
 m_lsHost.TryAdd(host);
 }
 catch (Exception ex)
 {
 Console.WriteLine("出現異常：" + ex.Message);
 m_log.ErrorFormat(ex.Message + ex.StackTrace);
 }
}

WCF服務端再也不用寫Service層瞭 

四、當我需要添加一個WCF接口，以實現一個查詢功能，比如查詢所有組織機構，重構前，我需要在7層添加代碼，然後客戶端調用，重構後，我隻需要在3層添加代碼，然後客戶端調用

    1.在WCF接口層添加接口

    2.在服務端數據訪問接口層添加接口

    3.在服務端數據訪問實現層添加實現方法

    4.客戶端調用：var orgList = PF.Get<IBaseDataService>().GetOrgList();

    重構前，需要在7層添加代碼，雖然每層代碼都差不多，可以復制粘貼，但是復制粘貼也很麻煩啊，重構後省事多瞭，從此再也不怕寫增刪改查瞭

五、性能損失

主要是invocation.Method.Invoke比直接調用慢，耗時是直接調用的2、3倍，但是多花費的時間跟數據庫查詢耗時比起來，是微不足道的

以上就是WCF如何使用動態代理精簡代碼架構的詳細內容，更多關於WCF使用動態代理精簡代碼架構的資料請關註WalkonNet其它相關文章！

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