WCF 動態代理與攔截器-有解無憂

使用Castle.Core.dll實作，核心代碼是使用Castle.DynamicProxy.ProxyGenerator類的CreateInterfaceProxyWithoutTarget方法動態創建代理物件

NuGet上面Castle.Core的下載量1.78億之多

1.WCF服務端通過動態代理，在攔截器中校驗Ticket、處理例外

服務端動態代理工廠類ProxyFactory代碼：

using Castle.DynamicProxy;
using SunCreate.Common.Base;
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.Server.Service
{
    /// <summary>
    /// 動態代理工廠
    /// </summary>
    public class ProxyFactory
    {
        /// <summary>
        /// 攔截器快取
        /// </summary>
        private static ConcurrentDictionary<Type, IInterceptor> _interceptors = new ConcurrentDictionary<Type, IInterceptor>();

        /// <summary>
        /// 代理物件快取
        /// </summary>
        private static ConcurrentDictionary<Type, object> _objs = new ConcurrentDictionary<Type, object>();

        private static ProxyGenerator _proxyGenerator = new ProxyGenerator();

        /// <summary>
        /// 動態創建代理
        /// </summary>
        /// <typeparam name="T">介面</typeparam>
        public static T CreateProxy<T>()
        {
            Type interfaceType = typeof(T);

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

            return (T)_objs.GetOrAdd(interfaceType, type => _proxyGenerator.CreateInterfaceProxyWithoutTarget(interfaceType, interceptor)); //根據介面型別動態創建代理物件，介面沒有實作類
        }
    }
}

View Code

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.Server.Service
{
    /// <summary>
    /// 攔截器
    /// </summary>
    /// <typeparam name="T">介面</typeparam>
    public class ProxyInterceptor<T> : IInterceptor
    {
        private static ILog _log = LogManager.GetLogger(typeof(ProxyInterceptor<T>));

        private T _impl;

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

        /// <summary>
        /// 攔截方法
        /// </summary>
        public void Intercept(IInvocation invocation)
        {
            //準備引數
            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())
                {
                    invocation.ReturnValue = invocation.Method.Invoke(_impl, valArr);
                }
            }
            catch (Exception ex)
            {
                _log.Error("ProxyInterceptor " + typeof(T).Name + " " + invocation.Method.Name + " 例外", ex);
            }

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

View Code

如何使用：

public List<EscortTask> GetEscortTaskList()
{
    var impl = ProxyFactory.CreateProxy<SunCreate.InfoPlatform.Server.Bussiness.IBussDataImp>();
    return impl.GetEscortTaskList();
}

View Code

這里不用再寫try catch

2.WCF客戶端通過動態代理，在攔截器中添加Ticket、處理例外、Close物件

客戶端動態代理工廠類ProxyFactory代碼：

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>
    /// 動態代理工廠
    /// </summary>
    public class ProxyFactory
    {
        /// <summary>
        /// 攔截器快取
        /// </summary>
        private static ConcurrentDictionary<Type, IInterceptor> _interceptors = new ConcurrentDictionary<Type, IInterceptor>();

        /// <summary>
        /// 代理物件快取
        /// </summary>
        private static ConcurrentDictionary<Type, object> _objs = new ConcurrentDictionary<Type, object>();

        private static ProxyGenerator _proxyGenerator = new ProxyGenerator();

        /// <summary>
        /// 動態創建代理
        /// </summary>
        /// <typeparam name="T">介面</typeparam>
        public static T CreateProxy<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)); //根據介面型別動態創建代理物件，介面沒有實作類
        }
    }
}

View Code

客戶端攔截器類ProxyInterceptor<T>代碼：

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">介面</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)
        {
            //準備引數
            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 = https://www.cnblogs.com/s0611163/archive/2020/12/18/HI.Get().GetValue();
                    ((IChannel)server).Close();
                }
                catch (Exception ex)
                {
                    _log.Error("ProxyInterceptor " + typeof(T).Name + " " + invocation.Method.Name + " 例外", ex);
                    ((IChannel)server).Abort();
                }
            }

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

View Code

如何使用：

public List<EscortTask> GetEscortTaskList()
{
    var service = ProxyFactory.CreateProxy<SunCreate.InfoPlatform.Contract.IBussDataService>();
    return service.GetEscortTaskList();
}

View Code

這里不用再寫try catch

3.性能損失

主要是invocation.Method.Invoke比直接呼叫慢，耗時是直接呼叫的2、3倍，但是多花費的時間跟資料庫查詢耗時比起來，是微不足道的

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標籤：.NET技术

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