VB使用XMLHTTP实现Post与Get的方法

本文所述为visual basic6.0的一个模块方法，是使用XMLHTTP实现Post与Get功能，虽然是一个老代码，但是可以替代Inet控件，实现数据通讯。很值得学习借鉴一下。

主要模块代码如下：

'==========================================================
'| 模 块 名 | XMLHTTP
'| 说  明 | 替代Inet控件，实现数据通讯
'==========================================================Public Enum DataEnum
  ResponseText = 1
  ResponseBody = 2
End Enum
 
Public Function GetData(ByVal Url As String, ByVal DataStic As DataEnum) As Variant
  
  On Error GoTo ERR:
  Dim XMLHTTP As Object
  Dim DataS As String
  Dim DataB() As Byte
  
  Set XMLHTTP = CreateObject("Microsoft.XMLHTTP")
  
  XMLHTTP.Open "get", Url, True
  XMLHTTP.send
  
  While XMLHTTP.ReadyState <> 4
    DoEvents
  Wend
  '--------------------------------------函数返回
  Select Case DataStic
  Case ResponseText
    '--------------------------------直接返回字符串
    DataS = XMLHTTP.ResponseText
    GetData = DataS
  Case ResponseBody
    '--------------------------------直接返回二进制
    DataB = XMLHTTP.ResponseBody
    GetData = DataB
  Case ResponseBody + ResponseText
    '------------------------------二进制转字符串[直接返回字串出现乱码时尝试]
    DataS = BytesToStr(XMLHTTP.ResponseBody)
    GetData = DataS
  Case Else
    '--------------------------------无效的返回
    GetData = ""
  End Select
  '--------------------------------------释放空间
  Set XMLHTTP = Nothing
  Exit Function
ERR:
  GetData = ""
End Function
 
Public Function PostData(ByVal StrUrl As String, ByVal StrData As String, ByVal DataStic As DataEnum) As Variant
  On Error GoTo ERR:
  
  Dim XMLHTTP As Object
  Dim DataS As String
  Dim DataB() As Byte
  
  Set XMLHTTP = CreateObject("Microsoft.XMLHTTP")
  
  XMLHTTP.Open "POST", StrUrl, True
  XMLHTTP.setRequestHeader "Content-Length", Len(PostData)
  XMLHTTP.setRequestHeader "CONTENT-TYPE", "application/x-www-form-urlencoded"
  XMLHTTP.send (StrData)
  
  Do Until XMLHTTP.ReadyState = 4
    DoEvents
  Loop
  '-----------------------------函数返回
  Select Case DataStic
  Case ResponseText
    '--------------------------------直接返回字符串
    DataS = XMLHTTP.ResponseText
    PostData = DataS
  Case ResponseBody
    '--------------------------------直接返回二进制
    DataB = XMLHTTP.ResponseBody
    PostData = DataB
  Case ResponseBody + ResponseText
    '---------------------------二进制转字符串[直接返回字串出现乱码时尝试]
    DataS = BytesToStr(XMLHTTP.ResponseBody)
    PostData = DataS
  Case Else
    '--------------------------------无效的返回
    PostData = ""
  End Select
  '------------------------------------释放空间
  Set XMLHTTP = Nothing
  Exit Function
ERR:
  PostData = ""
End Function
 
Function BytesToStr(ByVal vIn) As String
  strReturn = ""
  For i = 1 To LenB(vIn)
    ThisCharCode = AscB(MidB(vIn, i, 1))
    If ThisCharCode < &H80 Then
      strReturn = strReturn & Chr(ThisCharCode)
    Else
      NextCharCode = AscB(MidB(vIn, i + 1, 1))
      strReturn = strReturn & Chr(CLng(ThisCharCode) * &H100 + CInt(NextCharCode))
      i = i + 1
    End If
  Next
  BytesToStr = strReturn
End Function