Question

Exception Details: System.Web.HttpException: Request is not available in this context

Source Error:

Line 7:     Private Sub Application_Start(sender As Object, e As EventArgs)
Line 8:     ' Caching the tracker image in memory
Line 9:     Dim trackerImg As Byte() = File.ReadAllBytes(Context.Request.MapPath(ConfigurationManager.AppSettings("SD_Tut_ImageFileLocation")))
Line 10:    Application(ConfigurationManager.AppSettings("SD_Tut_ImageFileKeyName")) = trackerImg

错误在第9行

这是Global.asax代码

<%@ Application Language="vb" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Collections.Generic" %>
<%@ Import Namespace="Stardeveloper.Tutorial" %>

<script runat="server">
   Private Sub Application_Start(sender As Object, e As EventArgs)
    ' Caching the tracker image in memory
    Dim trackerImg As Byte() = File.ReadAllBytes(Context.Request.MapPath(ConfigurationManager.AppSettings("SD_Tut_ImageFileLocation")))
    Application(ConfigurationManager.AppSettings("SD_Tut_ImageFileKeyName")) = trackerImg

    ' Creating a new request queue collection
    Dim queueCapacity As Integer = Convert.ToInt32(ConfigurationManager.AppSettings("SD_Tut_TrackerRequestsToCache"))
    Dim trackerReqQueue As New Queue(Of TrackerRequest)(queueCapacity)
    Application(ConfigurationManager.AppSettings("SD_Tut_TrackerCachedRequestsKeyName")) = trackerReqQueue
End Sub

Private Sub Application_End(sender As Object, e As EventArgs)
    ' Storing the queued tracker reqs to database
    Dim trackerReqQueue As Queue(Of TrackerRequest) = DirectCast(Application(ConfigurationManager.AppSettings("SD_Tut_TrackerCachedRequestsKeyName")), Queue(Of TrackerRequest))
    Tracker.FlushRequestQueueCache(trackerReqQueue)
End Sub

</script>

Answer 1

我们正在处理哪个版本的IIS？如果是7或更高版本，则会发生可能导致此行为的更改。

请参阅this article.

Answer 2

<{1}}上无法使用

Request。

当您的Web应用程序启动并且此启动与任何页面请求无关时，

Application_Start将被执行，因为此时页面请求尚未发生。

根据您的需要，您可以改为使用Application_Start。

Answer 3

在此查找how to get Application_Start (in Global.asax.cs) to be called before requests in asmx web service on IIS 6.0

检查可能更合适这在BeginRequest方法中而不是Application_Start 因为第一个请求可能是当地但后来你可以打电话给应用于其他一些领域和它将不再是本地的。

在此上下文中不提供请求

3 个答案: