客户端代理的作用

客户端代理的作用
•在对象里做了一个标记
–“__type” = “ComplexType.Color”
•服务器端根据标记选择反序列化的目标类型
•可出现“多态”效果

aspx

    <form id="form1" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server">
            <Services>
                <asp:ServiceReference Path="EmployeeService.asmx" InlineScript="true" />
            </Services>
        </asp:ScriptManager>
        
        <div>Years:<input type="text" id="txtYears" /></div>
        <div>
            Status:
            <select id="comboStatus" style="150px;">
                <option value="ComplexType.Intern">Intern</option>
                <option value="ComplexType.Vendor">Vendor</option>
                <option value="ComplexType.FulltimeEmployee">FTE</option>
            </select>
        </div>
        
        <input type="button" onclick="calculateSalary()" value="Calculate!" />
        
        <br />
        <b>Result:</b>
        <div id="result"></div>
        
        <script language="javascript" type="text/javascript">
            function calculateSalary()
            {
                var emp = new Object();
                emp.__type = $get("comboStatus").value;
                
                emp.Years = parseInt($get("txtYears").value, 10);
                
                EmployeeService.CalculateSalary(emp, onSucceeded);
            }
                
            function onSucceeded(result)
            {
                $get("result").innerHTML = result;
            }
        </script>
    </form>

定义一个emp的Object对象，指定“__type”（何种类型对象，是要转换成相应的服务器端的类型的）的值，两个下划线“_”加上“type”

Employees.cs

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace ComplexType
{
    public abstract class Employee
    {
        private int _Years;
        public int Years
        {
            get
            {
                return this._Years;
            }
            set
            {
                this._Years = value;
            }
        }

        public string RealStatus
        {
            get
            {
                return this.GetType().Name;
            }
        }

        public abstract int CalculateSalary();
    }

    public class Intern : Employee
    {
        public override int CalculateSalary()
        {
            return 2000;
        }
    }

    public class Vendor : Employee
    {
        public override int CalculateSalary()
        {
            return 5000 + 1000 * (Years - 1);
        }
    }

    public class FulltimeEmployee : Employee
    {
        public override int CalculateSalary()
        {
            return 15000 + 2000 * (Years - 1);
        }
    }
}

这里的Employee类是一个抽象类，它必须被继承才能过使用

EmployeeService.asmx

<%@ WebService Language="C#" Class="EmployeeService" %>

using System;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Script.Services;
using ComplexType;


/// <summary>
/// Summary description for EmployeeService
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[ScriptService]
public class EmployeeService : System.Web.Services.WebService
{
    [WebMethod]
    [GenerateScriptType(typeof(Intern))]
    [GenerateScriptType(typeof(Vendor))]
    [GenerateScriptType(typeof(FulltimeEmployee))]
    public string CalculateSalary(Employee employee)
    {
        return "I'm " + employee.RealStatus +
            ", my salary is " + employee.CalculateSalary() + ".";
    }
}

这里的CalculateSalary方法指定要生成的参数类型不是Employee而是继承Employee的类的Intern、Vendor、FulltimeEmployee的子类，是因为Employee是抽象类，在传入参数时只要传入Intern、Vendor、FulltimeEmployee中的一种就可以了。