管理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服务方法的XML Web服务：ServerUsage和PerSessionServerUage。ServerUsage是一个点击计数器，用于访问ServerUsage XML Web服务方法时计数，而不管客户端如何与XML Web服务方法通信。例如，如果三个客户端连续地调用ServerUsage XML Web服务方法，最后一个接收一个返回值3。而PerSessionServiceUsage则是用于一个特别的客户端会话的计数器。如果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相同的结果。

[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