基本使用方式
赵劼
 MSDN特邀讲师
 [email][email protected][/email]
本次课程内容包括
    • 客户端访问WebService基础
    • 客户端访问PageMethod基础
    • 错误处理
    • 复杂数据类型使用基础
    • 客户端代理使用细节
收听本次课程需具备的条件
    • 了解.NET Framework开发
    • 熟悉JavaScript开发( 应知道怎么调用方法,回调函数的概念
一、服务器端释放WebService方法
    • 编写一个普通的ASP.NET WebService
    • 为WebService类添加自定义属性标记
        – ScriptServiceAttribute
    • 释放WebService方法
        – 访问级别为public( 首先基本public权限的方法
        – 使用WebMethodAttribute进行标记
    • 为页面中的ScriptManager(Proxy)引入asmx文件
二、客户端访问WebService
    • [Namespaces.]ClassName.MethodName ( 命名空间 -> 类 -> 方法
    • 依次传入参数
    • 传入一个方法做为成功后的回调函数
    • 即使没有返回值也会调用回调函数(因为它只是通知你事件已经处理完毕)
DEMO 1客户端访问WebService基础
WebServiceFoundation.asmx
 
<% @ WebService Language = " C# "  Class = " Sample.WebServiceFoundation "   %>

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

namespace  Sample
{
    [WebService(Namespace 
= "[url]http://tempuri.org/[/url]")]
    [WebServiceBinding(ConformsTo 
= WsiProfiles.BasicProfile1_1)]
    [ScriptService]   
//要释放时此处必须标写
    public class WebServiceFoundation : System.Web.Services.WebService //继承WebService类
    
{
        [WebMethod]
        
public int GetRandom()
        
{
            
return new Random(DateTime.Now.Millisecond).Next();
        }


        [WebMethod]
        
public int GetRangeRandom(int minValue, int maxValue)
        
//在一个区间获得一个随机数
            
return new Random(DateTime.Now.Millisecond).Next(minValue, maxValue);
        }

    }

}
 
1_WebServiceFoundation.aspx
 
<% @ Page Language = " C# "  AutoEventWireup = " true "  CodeFile = " 1_WebServiceFoundation.aspx.cs "  Inherits = " _1_WebServiceFoundation "   %>

DOCTYPE html PUBLIC  " -//W3C//DTD XHTML 1.0 Transitional//EN "   " [url]http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd[/url] " >

< html xmlns = " [url]http://www.w3.org/1999/xhtml[/url] "   >
< head runat = " server " >
    
< title > Untitled Page title >
head >
< body >
    
< form id = " form1 "  runat = " server " >
        
< asp:ScriptManager ID = " ScriptManager1 "  runat = " server "  ScriptMode = " Debug " >
            
< Services >
                
< asp:ServiceReference Path = " WebServiceFoundation.asmx "  InlineScript = " true "   />   // InlineScript 默认为false
             Services >
        
asp:ScriptManager >
        
        
< input type = " button "  value = " Get Random "  onclick = " getRandom() "   />
        
< input type = " button "  value = " Get Range Random "  onclick = " getRandom(50, 100) "   />
        
        
< script language = " javascript "  type = " text/javascript " >
            function getRandom(minValue, maxValue)
            
{ //客户端提供一个类似重载的功能
                
if (arguments.length != 2)
                
{
                    Sample.WebServiceFoundation.GetRandom(getRandomSucceeded);
                }

                
else
                
{
                    Sample.WebServiceFoundation.GetRangeRandom(minValue, maxValue, getRandomSucceeded);
                }

            }

            
            function getRandomSucceeded(result)
            
{
                alert(result);
            }

        
script >
    
form >
body >
html >
arguments:在JavaScript方法被调用时,都会初始化一个arguments这么一个对象,可当作一个数组类使用,但实际上是一个object,存放的就是这个方法调用时实际传入的参数
三、客户端访问PageMethod
    • 服务器端
        – 只能在aspx页面中定义
        – 只能是公开静态方法( static,无法在方法中访问页面控件
        – 使用WebMethodAttribute标记
        – ScriptManager的EnablePageMethods属性设为true ( EnablePageMethods默认为false
    • 客户端
        – 通过PageMethods.MethodName访问
DEMO 2 客户端访问PageMethods基础
2_PageMethods.aspx
 
<% @ Page Language = " C# "  AutoEventWireup = " true "  CodeFile = " 2_PageMethods.aspx.cs "  Inherits = " _2_PageMethods "   %>

DOCTYPE html PUBLIC  " -//W3C//DTD XHTML 1.0 Transitional//EN "   " [url]http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd[/url] " >

< html xmlns = " [url]http://www.w3.org/1999/xhtml[/url] "   >
< head runat = " server " >
    
< title > Untitled Page title >
head >
< body >
    
< form id = " form1 "  runat = " server " >
        
< asp:ScriptManager ID = " ScriptManager1 "  runat = " server "  EnablePageMethods ="true"   />
        
        
< input type = " button "  value = " Get Current Time "  onclick = " getCurrentTime() "   />
    
        
< script language = " javascript "  type = " text/javascript " >
            function getCurrentTime()
            
{
                PageMethods.GetCurrentTime(getCurrentTimeSucceeded);
            }

            
            function getCurrentTimeSucceeded(result)
            
{
                alert(result);
            }

        
script >
    
form >
body >
html >
 
2_PageMethods.aspx.cs 
using  System;
using  System.Data;
using  System.Configuration;
using  System.Collections;
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;
using  System.Web.Services;

public   partial   class  _2_PageMethods : System.Web.UI.Page
{
    
protected void Page_Load(object sender, EventArgs e)
    
{

    }


    [WebMethod]
    
public static DateTime GetCurrentTime()
    
{
        
return DateTime.UtcNow; //得到一个UTC时间
    }

}

 
运行结果:
当点击button时将 弹出
 Mon May 14 15:11:57 UTC+0800 2007
四、错误处理
    • 调用时可以提供一个额外的错误回调函数
    • 包括超时和服务器端抛出的异常
    • 超时只能设置在WebService级别
        – 或者设置在PageMethods对象上
        – 无法在每个Method Call时指定( 只能在Page中设定
    • Sys.Net.WebServiceError (是个类)
        – timedout、message、exceptionType、stackTrace属性
只有timeout为布尔型,其他都为字符型
  DEMO 3 错误处理
ErrorHandling.asmx
 
<% @ WebService Language = " C# "  Class = " ErrorHandling "   %>

using  System;
using  System.Web;
using  System.Web.Services;
using  System.Web.Services.Protocols;
using  System.Web.Script.Services;
using  System.Threading;

[WebService(Namespace 
=   " [url]http://tempuri.org/[/url] " )]
[WebServiceBinding(ConformsTo 
=  WsiProfiles.BasicProfile1_1)]
[ScriptService]
public   class  ErrorHandling  : System.Web.Services.WebService
{
    [WebMethod]
    
public int GetDivision(int a, int b)
    
{
        
return a / b;   //当a b为浮点数时,b为0时,不返回错误,而是返回一个无穷大的数
    }


    [WebMethod]
    
public int Timeout()
    
{
        Thread.Sleep(
5000);
        
return 0;
    }

}


 
3_ErrorHandling.aspx
 
<% @ Page Language = " C# "  AutoEventWireup = " true "  CodeFile = " 3_ErrorHandling.aspx.cs "  Inherits = " _3_ErrorHandling "   %>

DOCTYPE html PUBLIC  " -//W3C//DTD XHTML 1.0 Transitional//EN "   " [url]http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd[/url] " >

< html xmlns = " [url]http://www.w3.org/1999/xhtml[/url] "   >
< head runat = " server " >
    
< title > Untitled Page title >
head >
< body >
    
< form id = " form1 "  runat = " server " >
        
< asp:ScriptManager ID = " ScriptManager1 "  runat = " server " >
            
< Services >
                
< asp:ServiceReference Path = " ErrorHandling.asmx "   />
            
Services >
        
asp:ScriptManager >
        
        
< input type = " button "  value = " getDivision "  onclick = " getDivision(5, 0) "   />
        
< input type = " button "  value = " timeout "  onclick = " timeout() "   />
        
        
< script language = " javascript "  type = " text/javascript " >
            function getDivision(a, b)
            
{
                ErrorHandling.GetDivision(a, b, 
null, failedCallback);
                                                                                     
//(a b)为传入的参数,null为正确运行以后回调处理的的方法名,此处为空,表示不处理。
                                                                                    
//failedCallback为出错时处理的方法名
            }

            
            function timeout()
            
{
                ErrorHandling.set_timeout(
2000); //当不设置超时时间时,将不作任何处理
                ErrorHandling.Timeout(
null, failedCallback);
            }

            
            function failedCallback(error)
            
{
                var message 
= String.format(
                    
"Timeout: {0} Message: {1} ExceptionType: {2} StackTrace: {3}",
                    error.get_timedOut(),
                    error.get_message(),
                    error.get_exceptionType(),
                    error.get_stackTrace());
            
                alert(message);
            }

        
script >
    
form >
body >
html >