使用XmlInclude解决WebService调用时无法识别子类的异常

一、定义抽象类及子类，WebMethod实际返回子类参数

  //使用XmlInclude解决WebService调用时无法识别子类的异常
    [System.Xml.Serialization.XmlInclude(typeof(WageEmploeyee)), System.Xml.Serialization.XmlInclude(typeof(Boss))]
    public abstract class EmployeeData
    {
        //Required by XmlSerializer
        public EmployeeData() { }

        public string Name { get; set; }

        public string SSN { get; set; }

        public abstract double ComputerPay();
    }

    public class WageEmploeyee : EmployeeData
    {
        public double Wage { get; set; }

        public double Hours { get; set; }

        public override double ComputerPay()
        {
            return this.Wage * this.Hours;
        }
    }

    public class Boss : EmployeeData
    {
        public double Salary { get; set; }

        public override double ComputerPay()
        {
            return this.Salary;
        }
    }

2、WebMethod方法（根据传入的参数实例化不同的子类）

  public class WebService1 : System.Web.Services.WebService
    {

        [WebMethod]
        public EmployeeData GetEmployee(int id)
        {
            if (id == 1)
            {
                return new Boss();
            }

            return new WageEmploeyee();
        }
    }