1
我做了簡單的網頁。當它用查詢字符串調用時，它會增加應用程序變量。 3秒後，線程完成變量減少。更改應用程序變量沒有給予正確的結果
問題是，當我打開2個瀏覽器頁面（或mozilla）並從一個頁面調用並從其他頁面獲取結果時，一切正常。但是當我使用多線程測試應用程序撥打200或更多的電話時，號碼不會回到零。它不會像240或20一樣保持相同的數字。每次它不同但不是零。
page_load事件準備自動化進程。我的多線程應用程序調用此頁面，如http://localhost:4444/test.aspx?i=anything，因此頁面automaticallu將1添加到變量「x」並啓動線程。變量應該在3秒後減1，總數應該爲零。但不是 ？？？
重要：當我在我的測試應用程序中使用1個線程來調用此網頁時，它「起作用」很好。例如，它有時會達到680並返回到零。如果我使用2個線程來調用頁面，那麼結果總是「不一致」。
有趣的是不是如果我使用SQL Server，並保持變量存在，並增加與
UPDATE test SET count=count + 1
UPDATE test SET count=count - 1
我看不出有什麼問題，即使有20個併發連接/減少使用應用程序變量。
有什麼建議嗎？
Partial Class test
Inherits System.Web.UI.Page
Dim _resetEvent As New AutoResetEvent(False)
Protected Sub cmdWriteVariable_Click(sender As Object, e As EventArgs) Handles cmdWriteVariable.Click
Response.Write(Application("x").ToString)
End Sub
Protected Sub cmdIncreaseValue_Click(sender As Object, e As EventArgs) Handles cmdIncreaseValue.Click
If Application("x") Is Nothing Then Application("x") = 0
Application.Lock()
Application("x") = CInt(Application("x").ToString) + 1
Application.UnLock()
Response.Write(Application("x").ToString)
End Sub
Protected Sub Async_start()
Dim workerObject As New myTestAsyncClass(_resetEvent)
workerObject.ad = "anyname"
Dim ctx As HttpContext = HttpContext.Current
Dim workerThread As New Thread(New ThreadStart(Sub()
HttpContext.Current = ctx
workerObject.DoWork2(ctx)
End Sub))
workerThread.Start()
End Sub
Protected Sub cmdReset_Click(sender As Object, e As EventArgs) Handles cmdReset.Click
Application("x") = 0
End Sub
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If Application("x") Is Nothing Then Application("x") = 0
If Request.QueryString("i") IsNot Nothing Then
Application.Lock()
Application("x") = CInt(Application("x").ToString) + 1
Application.UnLock()
Async_start()
End If
End Sub
End Class
，這是線程類：
Imports Microsoft.VisualBasic
Imports System.Threading
Public Class myTestAsyncClass
Dim _resetEvent As AutoResetEvent = Nothing
Public ad As String
Public Sub New(resetEvent As AutoResetEvent)
_resetEvent = resetEvent
End Sub
Public Sub DoWork2(state As Object)
Try
Dim context As HttpContext = TryCast(state, HttpContext)
System.Threading.Thread.Sleep(3000)
Dim x As Integer = CInt(context.Application("x").ToString)
x = x - 1
context.Application.Lock()
context.Application("x") = x.ToString
context.Application.UnLock()
Finally
_resetEvent.[Set]()
End Try
End Sub
End Class
和aspx頁面，以防萬一：其簡單的3個按鍵。寫入變量，重置爲零並增加1.打開2個瀏覽器，單擊多次增加並從其他瀏覽器單擊寫入變量按鈕。你會看到它的工作正常。可以說10和3秒後變量變爲零。
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="test.aspx.vb" Async="true" Inherits="test" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="cmdIncreaseValue" runat="server" Text="increasevalue" />
<br />
<br />
<asp:Button ID="cmdWriteVariable" runat="server" Text="write app variable" />
<br />
<br />
<asp:Button ID="cmdReset" runat="server" Text="set varable to 0" />
</div>
</form>
</body>
</html>