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 = " width: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。