Silently download file via HttpWebRequest from a WebBrowser with HTTPS

!?!@?$?!@$?!@? Finally!!! It was so much work, I had to share!



After hours and hours (literally 7 hours) of searching testing I finally was able to open a file transfer silently in the background, in which the link was pulled from a webbrowser which has already logged in with HTTPS using cookies and then I transfered the cookie over to the HttpWebRequest.

I used this to open XML and XLS files to read data from.

Talk about a Pain! (ITA)

Start with this:

Code:

---

Const INTERNET_COOKIE_HTTPONLY As Integer = &H2000
    Declare Function InternetGetCookieEx Lib "wininet.dll" Alias "InternetGetCookieExA" (ByVal pchURL As String, ByVal pchCookieName As String, _
        ByVal pchCookieData As System.Text.StringBuilder, ByRef pcchCookieData As Integer, ByVal flags As Integer, ByVal reserved As Integer) As <MarshalAs(UnmanagedType.Bool)> Boolean



    Public Function GetGlobalCookies(ByVal uri As String) As String
        Dim datasize As UInteger = 8192
        Dim cookieData As New StringBuilder(CInt(datasize))
        'MsgBox(InternetGetCookieEx(uri, Nothing, cookieData, datasize, INTERNET_COOKIE_HTTPONLY, IntPtr.Zero))
        If InternetGetCookieEx(uri, Nothing, cookieData, datasize, INTERNET_COOKIE_HTTPONLY, IntPtr.Zero) AndAlso cookieData.Length > 0 Then
            Return cookieData.ToString().Replace(";"c, ","c)
        Else
            Return Nothing
        End If
    End Function

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Then your sub to call the download of your "link"

Code:

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Private Sub DownloadFile(ByVal remoteFilename As Uri, ByVal localFilename As String)
        Dim webRequest As HttpWebRequest = Net.WebRequest.Create(remoteFilename)
        Dim bytesProcessed As Integer = 0
        Dim remoteStream As Stream
        Dim localStream As Stream
        Dim response As WebResponse

        webRequest.CookieContainer = New CookieContainer
        webRequest.CookieContainer.SetCookies(WebBrowser2.Document.Url, GetGlobalCookies(WebBrowser1.Document.Url.AbsoluteUri))

        response = webRequest.GetResponse()
        If Not response Is Nothing Then
            remoteStream = response.GetResponseStream()
            localStream = File.Create(localFilename)

            'Declare buffer as byte array
            Dim myBuffer As Byte()
            'Byte array initialization
            ReDim myBuffer(1024)


            Dim bytesRead As Integer
            bytesRead = remoteStream.Read(myBuffer, 0, 1024)
            Do While (bytesRead > 0)
                localStream.Write(myBuffer, 0, bytesRead)
                bytesProcessed += bytesRead
                bytesRead = remoteStream.Read(myBuffer, 0, 1024)
            Loop
            localStream.Close()
        End If
    End Sub

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...and then to call the URL from the HTML page...

Code:

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Dim anchors As HtmlElementCollection = WebBrowser2.Document.GetElementsByTagName("a")

For Each anc As HtmlElement In anchors
                        If anc.InnerText = frmMain.ListBox1.SelectedItem Then
'Call the download, setting the URL and the local path to save the file.
                            DownloadFile(New Uri(anc.GetAttribute("href")), "c:\temp\filename.xxx")
                        End If

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I even delete the file when I exit, and I'll share that with you guys as well. :D
;)

Code:

---

Private Sub DeletePath()
        Dim KillFile As String
        KillFile = path2 'Path 2 = a constant path thoughout program
        'Check that file exists
        If Len(Dir$(KillFile)) > 0 Then
            'First remove readonly attribute, if set
            SetAttr(KillFile, vbNormal)
            'Then delete the file
            Kill(KillFile)
        End If

    End Sub

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