天天看点

VB6通过ASP网页实现C/S模式

 C/S模式一般都是用winsock来相互通信,实现双方互动。

用ASP网页来连接(不能称之为通信),只能C对S发送信息或请求一些信息,

S是不能主动来连接C,发信息给C。

一、C端

既然是要访问ASP页,这里有二种方式。

1、API写的访问模块

Option Explicit

''<API 宣告,API 常数>

Public Declare Function InternetOpen Lib "wininet.dll" _

          Alias "InternetOpenA" _

                  (ByVal lpszCallerName As String, _

                  ByVal dwAccessType As Long, _

                  ByVal lpszProxyName As String, _

                  ByVal lpszProxyBypass As String, _

                  ByVal dwFlags As Long) As Long

  Public Declare Function InternetConnect Lib "wininet.dll" _

          Alias "InternetConnectA" _

                  (ByVal hInternetSession As Long, _

                  ByVal lpszServerName As String, _

                  ByVal nProxyPort As Integer, _

                  ByVal lpszUsername As String, _

                  ByVal lpszPassword As String, _

                  ByVal dwService As Long, _

                  ByVal dwFlags As Long, _

                  ByVal dwContext As Long) As Long

  Public Declare Function InternetReadFile Lib "wininet.dll" _

          (ByVal hFile As Long, _

                  ByVal sBuffer As String, _

                  ByVal lNumBytesToRead As Long, _

                  lNumberOfBytesRead As Long) As Integer

  Public Declare Function HttpOpenRequest Lib "wininet.dll" _

          Alias "HttpOpenRequestA" _

                  (ByVal hInternetSession As Long, _

                  ByVal lpszVerb As String, _

                  ByVal lpszObjectName As String, _

                  ByVal lpszVersion As String, _

                  ByVal lpszReferer As String, _

                  ByVal lpszAcceptTypes As Long, _

                  ByVal dwFlags As Long, _

                  ByVal dwContext As Long) As Long

  Public Declare Function HttpSendRequest Lib "wininet.dll" _

          Alias "HttpSendRequestA" _

                  (ByVal hHttpRequest As Long, _

                  ByVal sHeaders As String, _

                  ByVal lHeadersLength As Long, _

                  ByVal sOptional As String, _

                  ByVal lOptionalLength As Long) As Boolean

  Public Declare Function InternetCloseHandle Lib "wininet.dll" _

                  (ByVal hInternetHandle As Long) As Boolean

  Public Declare Function HttpAddRequestHeaders Lib "wininet.dll" _

          Alias "HttpAddRequestHeadersA" _

                  (ByVal hHttpRequest As Long, _

                  ByVal sHeaders As String, _

                  ByVal lHeadersLength As Long, _

                  ByVal lModifiers As Long) As Integer

  Public Function PostInfo(ByVal WebServerAddress As String, _

                           ByVal Port As String, _

                           ByVal WebPageName As String, _

                           ByVal CommandString As String, _

                           Optional ByVal PostData As String = "") As String

          Dim hInternetOpen     As Long

          Dim hInternetConnect     As Long

          Dim hHttpOpenRequest     As Long

          Dim bRet     As Boolean

          hInternetOpen = 0

          hInternetConnect = 0

          hHttpOpenRequest = 0

          'Use   registry   access   settings.

          Const INTERNET_OPEN_TYPE_PRECONFIG = 0

          hInternetOpen = InternetOpen("http   generic", _

                                          INTERNET_OPEN_TYPE_PRECONFIG, _

                                          vbNullString, _

                                          vbNullString, _

                                          0)

          If hInternetOpen <> 0 Then

                  'Type   of   service   to   access.

                  Const INTERNET_SERVICE_HTTP = 3

                  Const INTERNET_DEFAULT_HTTP_PORT = 80

                  'Change   the   server   to   your   server   name

                  hInternetConnect = InternetConnect(hInternetOpen, _

                                                      WebServerAddress, _

                                                      Port, _

                                                      vbNullString, _

                                                      "HTTP/1.0", _

                                                      INTERNET_SERVICE_HTTP, _

                                                      0, _

                                                      0)

                  If hInternetConnect <> 0 Then

                      'Brings   the   data   across   the   wire   even   if   it   locally   cached.

                      Const INTERNET_FLAG_RELOAD = &H80000000

                      hHttpOpenRequest = HttpOpenRequest(hInternetConnect, _

                                                            "POST", _

                                                            WebPageName & CommandString, _

                                                            "HTTP/1.0", _

                                                            vbNullString, _

                                                            0, _

                                                            INTERNET_FLAG_RELOAD, _

                                                            0)

                      If hHttpOpenRequest <> 0 Then

                            Dim sHeader     As String

                            Const HTTP_ADDREQ_FLAG_ADD = &H20000000

                            Const HTTP_ADDREQ_FLAG_REPLACE = &H80000000

                            sHeader = "Content-Type:   application/x-www-form-urlencoded" & vbCrLf

                            'sHeader = "Content-Type:   multipart/form-data" & vbCrLf

                            bRet = HttpAddRequestHeaders(hHttpOpenRequest, _

                                sHeader, Len(sHeader), HTTP_ADDREQ_FLAG_REPLACE _

                                Or HTTP_ADDREQ_FLAG_ADD)

                            Dim lpszPostData     As String

                            Dim lPostDataLen     As Long

                            lpszPostData = PostData

                            'lPostDataLen = Len(lpszPostData)

                            lPostDataLen = LenB(StrConv(lpszPostData, vbFromUnicode))

                            bRet = HttpSendRequest(hHttpOpenRequest, _

                                          vbNullString, _

                                          0, _

                                          lpszPostData, _

                                          lPostDataLen)

                            Dim bDoLoop                             As Boolean

                            Dim sReadBuffer                     As String * 4096

                            Dim lNumberOfBytesRead       As Long

                            Dim sBuffer                             As String

                            bDoLoop = True

                            While bDoLoop

                              sReadBuffer = vbNullString

                              bDoLoop = InternetReadFile(hHttpOpenRequest, _

                                    sReadBuffer, Len(sReadBuffer), lNumberOfBytesRead)

                              sBuffer = sBuffer & _

                                        Left(sReadBuffer, lNumberOfBytesRead)

                              If Not CBool(lNumberOfBytesRead) Then bDoLoop = False

                            Wend

                            PostInfo = sBuffer

                            bRet = InternetCloseHandle(hHttpOpenRequest)

                      End If

                      bRet = InternetCloseHandle(hInternetConnect)

                  End If

                  bRet = InternetCloseHandle(hInternetOpen)

          End If

          PostInfo = sBuffer

  End Function

  Public Sub SplitAddr(ByVal addr$, srv$, script$)

  'Inputs:   The   full   url   including   http://

  '   Two   variables   that   will   be   changed

  '

  'Returns:   Splits   the   addr$   var   into   the   server   name

  '   and   the   script   path

      Dim i%

      i = InStr(addr$, "/")

      srv$ = Mid(addr$, i + 2, Len(addr$) - (i + 1))

      i = InStr(srv$, "/")

      script$ = Mid(srv$, i, Len(srv$) + 1 - i)

      srv$ = Left$(srv$, i - 1)

  End Sub

以上代码可以在网上搜索到,我修改了一下,支持中文传输。

把以上代码放到一个模块中即可。

调用PostInfo时,给出正确的参数即可。

这个函数的返回值就是你得到的信息,一个字符串,由S端生成。

2、可以用XMLHTTP来访问,我给出一个我实际用的upload file的函数

Public Function UploadFile() As Boolean

On Error GoTo UploadFile_Error

    m_UploadMessage = ""

    If Len(m_sFileName) = 0 Then

        m_UploadMessage = "未设置上传的文件。"

        UploadFile = False

        Exit Function

    End If

    Dim XMLDocument As New DOMDocument

    Dim ADOStream As New Stream

    Dim DOMElement As IXMLDOMElement

    Dim MyXMLHttp As New XMLHTTP

    XMLDocument.loadXML ("<?xml version=""1.0"" ?> <root/>")

    XMLDocument.documentElement.setAttribute "xmlns:dt", "urn:schemas-microsoft-com:datatypes"

    Set DOMElement = XMLDocument.createElement("File")

    DOMElement.dataType = "bin.base64"

    ADOStream.Type = adTypeBinary

    ADOStream.Open

    ADOStream.LoadFromFile m_sFileName

    DOMElement.nodeTypedValue = ADOStream.Read

    ADOStream.Close

    XMLDocument.documentElement.appendChild DOMElement

    MyXMLHttp.Open "POST", m_sWebPage, False, m_sUserName, m_sPassWord

    MyXMLHttp.send XMLDocument

    m_UploadMessage = MyXMLHttp.responseText

    If m_UploadMessage = "OK" Then

        m_UploadMessage = ""

        UploadFile = True

    Else

        UploadFile = False

    End If

UploadFile_Exit:

    m_sFileName = ""

    Set XMLDocument = Nothing

    Set ADOStream = Nothing

    Set DOMElement = Nothing

    Set MyXMLHttp = Nothing

    Exit Function

UploadFile_Error:

    UploadFile = False

    Debug.Print CStr(Now()) & "--->" & vbCrLf & _

             "ErrAddress:  VanFileTransfer->VanFileDownLoad->UploadFile" & vbCrLf & _

             "ErrNumber:   " & Err.Number & vbCrLf & _

             "Description: " & Err.Description & vbCrLf

    Err.Clear

    Resume UploadFile_Exit

End Function

同样,代码中的m_UploadMessage就是返回来的信息.

二、接着说S端

需要引用microsoft active server pages object library

1、添加ASP页的接口类

Private gMyServer As Server

Private gMySession As Session

Private gMyApplication As Application

Private gMyRequest As Request

Private gMyResponse As Response

这几个是ASP的对象,会ASP的人一看就知道。

Public Function OnStartPage(MyScriptingContext As ScriptingContext)

    Set gMyServer = MyScriptingContext.Server

    Set gMySession = MyScriptingContext.Session

    Set gMyApplication = MyScriptingContext.Application

    Set gMyRequest = MyScriptingContext.Request

    Set gMyResponse = MyScriptingContext.Response

End Function

Public Function OnEndPage()

    Set gMyServer = Nothing

    Set gMySession = Nothing

    Set gMyApplication = Nothing

    Set gMyRequest = Nothing

    Set gMyResponse = Nothing

End Function

这二个是ASP加载时和关闭时事件。我们用来得到对象实例和释放对象。

下面就是入口函数

public function MySubMain()

'gMyRequest中就是C给过来的一些数据,处理他

gMyResponse.Write “返回给C的数据”

end function

三、ASP页内容

<%

    set MyObject = server.createobject("工程名.接口类名")

    MyObject.MySubMain

    set MyObject = nothing

%>

把ASP页架起来就OK了。

C/S就可以通信了。

PS:如果有兴趣的朋友,可以向我索要最简单的完整实例。

继续阅读