实现契约接口

创建类库项目WcfService.Implementation，添加对WcfService.Contract的引用。通过EmployeeService类，继承和实现IEmployeeService中定义的契约服务接口。代码大致如下：

using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Net;
using System.ServiceModel.Activation;
using WcfService.Contract;
namespace WcfService.Implementation
{
    [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    public class EmployeeService : IEmployeeService
    {
        private static List<Employee> employees = new List<Employee>
        {
            new Employee{ Id = "001", Name="万事通", Department="开发部", Grade = "G4"},
            new Employee{ Id = "002", Name="害羞鬼", Department="人事部", Grade = "G6"},
            ......
         };
        public Employee GetEmployeeById(string id)
        {
            Employee employee = employees.FirstOrDefault(e => e.Id == id);
            if (null == employee)
            {
                WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.NotFound;
            }
            return employee;
        }
        public IEnumerable<Employee> GetAllEmployees()
        {
            return employees;
        }
        public void AddEmployee(Employee employee)
        {
            ......
        }
        public void UpdateEmployee(Employee employee)
        {
           ......
        }
        public void DeleteEmployee(string id)
        {
           .......
        }
    }
}

在EmployeeService类中，我们定义了一个Employee的List集合，用来存放Employee对象，以模拟实际应用中的数据对象的存取操作。前文契约中定义的HTTP协议的GET、POST、PUT、DELETE实际动作，将对应与EmployeeService类中对接口实现的具体功能。WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.NotFound; GetEmployeeById(string id)方法中的上述代码，指定了如果要获取的对象不存在时，当前WCF上下文应该返回的状态值。