using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;
using System.Web;

namespace Test
{
    public class MyOperationInterceptorAttribute : Attribute, IOperationBehavior
    {
        public void AddBindingParameters(OperationDescription operationDescription, BindingParameterCollection bindingParameters)
        { }
        public void ApplyClientBehavior(OperationDescription operationDescription, ClientOperation clientOperation)
        { }
        public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation)
        {
            dispatchOperation.Invoker = new MyInvoker(dispatchOperation.Invoker);
        }
        public void Validate(OperationDescription operationDescription)
        { }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.ServiceModel;
using System.ServiceModel.Dispatcher;
using System.ServiceModel.Web;
using System.Web;

namespace Test
{
    public class MyInvoker : IOperationInvoker
    {

        private readonly IOperationInvoker m_OldInvoker;

        public MyInvoker(IOperationInvoker inner)
        {
            m_OldInvoker = inner;
        }

        public object Invoke(object instance, object[] inputs, out object[] outputs)
        {
            try
            {
                //这里可以进行一些权限验证
                //do something
                object result = m_OldInvoker.Invoke(instance, inputs, out outputs);

                return result;
            }
            catch (Exception err)
            {
                outputs = new object[0];
                //do catch
                return null;
            }
            finally
            {

            }

        }

        public virtual object[] AllocateInputs()
        {
            return m_OldInvoker.AllocateInputs();
        }

        public IAsyncResult InvokeBegin(object instance, object[] inputs, AsyncCallback callback, object state)
        {
            return m_OldInvoker.InvokeBegin(instance, inputs, callback, state);
        }

        public object InvokeEnd(object instance, out object[] outputs, IAsyncResult result)
        {

            return m_OldInvoker.InvokeEnd(instance, out outputs, result);

        }

        public bool IsSynchronous
        {
            get
            {
                return m_OldInvoker.IsSynchronous;
            }
        }
    }
}

public class srvtest
    {
        [WebGet(UriTemplate = "", ResponseFormat = WebMessageFormat.Json)]
        [MyOperationInterceptor]
        public string Hello()
        {
            return "Hello" + DateTime.Now.ToString();
        }
     
        [WebGet(UriTemplate = "Index", ResponseFormat = WebMessageFormat.Json)]        
        public string Index()
        {
            return "Index" + DateTime.Now.ToString();
        }             
    }

在需要拦截的方法上添加 [MyOperationInterceptor]即可，不需要拦截的就不添加