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VB6 HTTP请求到VB.Net 2.0的转换

httpwebrequest vb6 vb.net .net

Simon · 技术社区 · 17 年前

我正在尝试将旧版VB6组件(不是我编写的)更新到.NET平台。有一个函数可将XML字符串发布到URL:

Function PostToUrl(ByRef psUrl, ByRef psData, Byref psResponseText, ByRef psErrorMsg, ByRef psUsername, ByRef psPassword)

    On Error Resume Next    
    Dim objWinHTTP

    PostToUrl = False
    psErrorMsg = ""
    psResponseText = ""
    Dim m_lHTTPREQUEST_SETCREDENTIALS_FOR_SERVER
    m_lHTTPREQUEST_SETCREDENTIALS_FOR_SERVER    =0  

    Set objWinHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")


    objWinHTTP.Open "POST", psUrl

    If psUsername <> "" Then
        Call objWinHTTP.SetCredentials(psUsername, psPassword, m_lHTTPREQUEST_SETCREDENTIALS_FOR_SERVER)
    End If
    objWinHTTP.SetRequestHeader "Host", "http://www.xxx.com/CSIHTTP.asp"
    objWinHTTP.SetRequestHeader "X-Method", "Submit"
    objWinHTTP.SetRequestHeader "Content-Type", "text/xml"

    objwinHTTP.setTimeouts 3000, 15000, 15000, 120000


    Call objWinHTTP.Send(psData)

    ' Handle errors  '


    If Err.Number <> 0 Then

        psErrorMsg = Err.Description & " test"
        PostToUrl = False

    ElseIf objWinHTTP.Status <> 200 AND objWinHTTP.Status <> 202 Then

        psErrorMsg = "(" & objWinHTTP.Status & ") " & objWinHTTP.StatusText
        PostToUrl = False

    Else

        psErrorMsg = objWinHTTP.ResponseText & "(" & objWinHTTP.Status & ") " & objWinHTTP.StatusText
        PostToUrl = True

    End If

    Set objWinHTTP = Nothing
End Function

Public Function PostXml(ByVal XML As String) As Boolean

        Try
            Dim URL As String = My.Settings.NTSPostURL 
            'TODO: supply username and password!  '
            Dim Bytes As Byte() = Me.Encoding.GetBytes(XML)
            Dim HTTPRequest As HttpWebRequest = DirectCast(WebRequest.Create(Me.PostURL), HttpWebRequest)
            Dim Cred As New NetworkCredential("username", "password", "http://www.xxx.com")

            With HTTPRequest
                .Method = "POST"
                .ContentLength = Bytes.Length
                .ContentType = "text/xml"
                .Credentials = Cred
                .Timeout = 120000
                .Method = "Submit"
            End With

            Using RequestStream As Stream = HTTPRequest.GetRequestStream()
                RequestStream.Write(Bytes, 0, Bytes.Length)
                RequestStream.Close()
            End Using

            Using Response As HttpWebResponse = DirectCast(HTTPRequest.GetResponse(), HttpWebResponse)

                If Response.StatusCode <> HttpStatusCode.OK Then

                    Dim message As String = [String].Format("POST failed. Received HTTP {0}", Response.StatusCode)

                    Throw New ApplicationException(message)

                End If

            End Using

        Catch ex As WebException
            Dim s As String = ex.Response.ToString() & " " & ex.Status.ToString()
            Throw
        End Try

    End Function

但是,当我运行.NET代码时,服务器在以下行返回错误“403禁止-协议错误”: Using Response As HttpWebResponse = DirectCast(HTTPRequest.GetResponse(), HttpWebResponse) . VB6代码运行良好。有人能找出这两者之间可能导致这种情况的任何差异吗?这让我左右为难。。。。

4 回复 | 直到 17 年前

Peter Lange 17 年前

当然,这只是一个猜测。

steamer25 17 年前

您是否尝试过从这两个来源捕获流量并进行比较?

我先试试小提琴手 http://www.fiddler2.com/fiddler2/ 这是一个免费的HTTP调试代理。

如果这不起作用,你可以试试WireShark,它是一个免费的协议分析器(级别稍微低一点,所以会有很多细节需要过滤掉)。 http://www.wireshark.org/

AnthonyWJones 17 年前

试着这样做:-

Dim myCache as New CredentialCache()
myCache.Add(New Uri("http://www.xxx.com"), "Basic", New NetworkCredential("username", "password"))

HTTPRequest.Credentials = myCache

这假设需要基本身份验证,另一个竞争者将是可能需要域的“摘要”或“NTLM”。例如,如果旧代码中的用户名文本类似于“域\用户名”,则您需要:-

Dim myCache as New CredentialCache()
myCache.Add(New Uri("http://www.xxx.com"), "NTLM", New NetworkCredential("username", "password", "domain"))

HTTPRequest.Credentials = myCache

顺便说一句,我同意steamer25,对于这类事情,你真的需要一个像fiddler这样的工具。

应用程序

<system.net>
    <defaultProxy enabled="false">
        <proxy proxyaddress="http://127.0.0.1:8888" bypassonlocal="False"/>
    </defaultProxy>
</system.net>

启动fiddler并将enabled属性轻弹为“true”。现在,您应该看到新代码试图与ASP服务器进行的对话。确保在使用新代码之前设置enabled=“false”,而不使用fiddler捕获。

Simon 17 年前

在经历了很多痛苦之后,我终于设法让它工作了。问题在于文本编码,我已将其更改为ASCII,并且一切正常:

Try
            Dim Bytes As Byte() = Me.Encoding.GetBytes(XML)
            Dim HTTPRequest As HttpWebRequest = DirectCast(WebRequest.Create(Me.PostURL), HttpWebRequest)

            With HTTPRequest
                .Method = "POST"
                .ContentLength = Bytes.Length
                .ContentType = "text/xml"
                .Credentials = New NetworkCredential("user", "password") 'myCache
            End With

            Using RequestStream As Stream = HTTPRequest.GetRequestStream()
                RequestStream.Write(Bytes, 0, Bytes.Length)
                RequestStream.Close()
            End Using

            Using Response As HttpWebResponse = DirectCast(HTTPRequest.GetResponse(), HttpWebResponse)

                Return Response.StatusCode

            End Using

        Catch ex As WebException
            Dim s As String = ex.Status.ToString
            Throw
        End Try

感谢所有帮助过我的人。全体投票。