VB.net httpwebrequest For loop hangs every 10 or so iterations
- by user574632
Hello, I am trying to loop through an array and perform an httpwebrequest in each iteration.
The code seems to work, however it pauses for a while (eg alot longer than the set timeout. Tried setting that to 100 to check and it still pauses) after every 10 or so iterations, then carries on working.
Here is what i have so far:
For i As Integer = 0 To numberOfProxies - 1
Try
'create request to a proxyJudge php page using proxy
Dim request As HttpWebRequest = HttpWebRequest.Create("http://www.pr0.net/deny/azenv.php")
request.Proxy = New Net.WebProxy(proxies(i)) 'select the current proxie from the proxies array
request.Timeout = 10000 'set timeout
Dim response As HttpWebResponse = request.GetResponse()
Dim sr As StreamReader = New StreamReader(response.GetResponseStream())
Dim pageSourceCode As String = sr.ReadToEnd()
'check the downloaded source for certain phrases, each identifies a type of proxy
'HTTP_X_FORWARDED_FOR identifies a transparent proxy
If pageSourceCode.Contains("HTTP_X_FORWARDED_FOR") Then
'delegate method for cross thread safe
UpdateListbox(ListBox3, proxies(i))
ElseIf pageSourceCode.Contains("HTTP_VIA") Then
UpdateListbox(ListBox2, proxies(i))
Else
UpdateListbox(ListBox1, proxies(i))
End If
Catch ex As Exception
'MessageBox.Show(ex.ToString) used in testing
UpdateListbox(ListBox4, proxies(i))
End Try
completedProxyCheck += 1
lblTotalProxiesChecked.CustomInvoke(Sub(l) l.Text = completedProxyCheck)
Next
I have searched all over this site and via google, and most responses to this type of question say the response must be closed. I have tried a using block, eg:
Using response As HttpWebResponse = request.GetResponse()
Using sr As StreamReader = New StreamReader(response.GetResponseStream())
Dim pageSourceCode As String = sr.ReadToEnd()
'check the downloaded source for certain phrases, each identifies a type of proxy
'HTTP_X_FORWARDED_FOR identifies a transparent proxy
If pageSourceCode.Contains("HTTP_X_FORWARDED_FOR") Then
'delegate method for cross thread safe
UpdateListbox(ListBox3, proxies(i))
ElseIf pageSourceCode.Contains("HTTP_VIA") Then
UpdateListbox(ListBox2, proxies(i))
Else
UpdateListbox(ListBox1, proxies(i))
End If
End Using
End Using
And it makes no difference (though i may have implemented it wrong) As you can tell im very new to VB or any OOP so its probably a simple problem but i cant work it out.
Any suggestions or just tips on how to diagnose these types of problems would be really appreciated.
