治理Web服务状态(2)

    

　　在下面示例中，appMyServiceUsage状态变量被访问来递增其值。下面的代码示例是一个使用两个XML Web服务方式的XML Web服务：ServerUsage和PerSessionServerUage。ServerUsage是一个点击计数器，用于访问ServerUsage XML Web服务方式时计数，而不管客户端如何与XML Web服务方式通信。例如，假如三个客户端连续地调用ServerUsage XML Web服务方式，最后一个接收一个返回值3。而PerSessionServiceUsage则是用于一个特殊的客户端会话的计数器。假如三个客户端连续地访问PerSessionServiceUsage，每个客户端都会在第一次调用的时候接收到一样的结果。

[C#] ＜%@ WebService Language=\"C#\" Class=\"ServerUsage\" %＞ using System.Web.Services; public class ServerUsage : WebService { 　[ WebMethod(Description=\"Number of times this service has been accessed.\") ] 　public int ServiceUsage() { 　　// If the XML Web service method hasn\\\'t been accessed, 　　// initialize it to 1. 　　if (Application[\"appMyServiceUsage\"] == null) 　　{ 　　　Application[\"appMyServiceUsage\"] = 1; 　　} 　　else 　　{ 　　　// Increment the usage count. 　　　Application[\"appMyServiceUsage\"] = ((int) Application[\"appMyServiceUsage\"]) + 1; 　　} 　　return (int) Application[\"appMyServiceUsage\"]; 　} 　[ WebMethod(Description=\"Number of times a particualr client session has accessed this XML Web service method.\",EnableSession=true) ] 　public int PerSessionServiceUsage() { 　　// If the XML Web service method hasn\\\'t been accessed, initialize 　　// it to 1. 　　if (Session[\"MyServiceUsage\"] == null) 　　{ 　　　Session[\"MyServiceUsage\"] = 1; 　　} 　　else 　　{ 　　　// Increment the usage count. 　　　Session[\"MyServiceUsage\"] = ((int) Session[\"MyServiceUsage\"]) + 1; 　　} 　　return (int) Session[\"MyServiceUsage\"]; 　} } [Visual Basic] ＜%@ WebService Language=\"VB\" Class=\"ServerUsage\" %＞ Imports System.Web.Services Public Class ServerUsage Inherits WebService ＜WebMethod(Description := \"Number of times this service has been accessed.\")＞ _ Public Function ServiceUsage() As Integer \\\' If the XML Web service method hasn\\\'t been accessed, initialize \\\' it to 1. If Application(\"appMyServiceUsage\") Is Nothing Then 　Application(\"appMyServiceUsage\") = 1 Else 　\\\' Increment the usage count. 　Application(\"appMyServiceUsage\") = _ 　CInt(Application(\"appMyServiceUsage\")) + 1 End If Return CInt(Application(\"appMyServiceUsage\")) End Function ＜WebMethod(Description := \"Number of times a particular client session has accessed this XML Web service method.\", EnableSession := True)＞ _ Public Function PerSessionServiceUsage() As Integer \\\' If the XML Web service method hasn\\\'t been accessed, \\\' initialize it to 1. If Session(\"MyServiceUsage\") Is Nothing Then 　Session(\"MyServiceUsage\") = 1 Else 　\\\' Increment the usage count. 　Session(\"MyServiceUsage\") = CInt(Session(\"MyServiceUsage\")) + 1 End If 　Return CInt(Session(\"MyServiceUsage\")) End Function End Class