سورس کد خواندن محتویات وب پیج (ویژوال بیسیک 6)

کد:
Read an internet web page with API calls



The following routine uses API calls to read/download an internet file. A routine demonstrating how to use this code can be found at the bottom of this post.



Option Explicit

Private Declare Function InternetOpen Lib "wininet" Alias "InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As Long

Private Declare Function InternetCloseHandle Lib "wininet" (ByVal hInet As Long) As Integer

Private Declare Function InternetReadFile Lib "wininet" (ByVal hFile As Long, ByVal sBuffer As String, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer

Private Declare Function InternetOpenUrl Lib "wininet" Alias "InternetOpenUrlA" (ByVal hInternetSession As Long, ByVal lpszUrl As String, ByVal lpszHeaders As String, ByVal dwHeadersLength As Long, ByVal dwFlags As Long, ByVal dwContext As Long) As Long





'Purpose     :  Retreview text from a web site

'Inputs      :  sURL                The URL and file name to extract the text from

'               [lBufferSize]       The number of characters to extract.

'                                   If value is -1 the reads the whole page.

'Outputs     :  The text found on the web site

'Notes       :  NOT SUITABLE FOR ACCESSING THE INTERNET THROUGH A ....... SERVER





Function InternetGetText(sURL As String, Optional lBufferSize As Long = -1) As String

    Dim lhOpen As Long, lhFile As Long, sBuffer As String, lRet As Long

    Const clBufferIncrement As Long = 2000

    Const scUserAgent = "VBUsers"

    Const INTERNET_OPEN_TYPE_PRECONFIG = 0, INTERNET_FLAG_EXISTING_CONNECT = &H20000000

    Const INTERNET_OPEN_TYPE_DIRECT = 1, INTERNET_OPEN_TYPE_PROXY = 3

    Const INTERNET_FLAG_RELOAD = &H80000000

    

    If lBufferSize = -1 Then

        'Create an arbitary buffer to read the whole file in parts

        sBuffer = String$(clBufferIncrement, Chr$(0))

    Else

        'Create a specified buffer size

        sBuffer = String$(lBufferSize, Chr$(0))

    End If

    'Create an internet connection

    lhOpen = InternetOpen(scUserAgent, INTERNET_OPEN_TYPE_DIRECT, vbNullString, vbNullString, 0)

    'Open the url

    lhFile = InternetOpenUrl(lhOpen, sURL, vbNullString, ByVal 0&, INTERNET_FLAG_RELOAD, ByVal 0&)

    If lhFile = 0 Then

        'Try using p

        InternetCloseHandle lhFile

        InternetCloseHandle lhOpen

        'Create an internet connection

        lhOpen = InternetOpen(scUserAgent, INTERNET_OPEN_TYPE_PRECONFIG, vbNullString, vbNullString, 0)

        'Open the url

        lhFile = InternetOpenUrl(lhOpen, sURL, vbNullString, ByVal 0&, INTERNET_FLAG_EXISTING_CONNECT, ByVal 0&)

    End If

    If lBufferSize = -1 And lhFile <> 0 Then

        'Read the whole page

        Do

            InternetReadFile lhFile, sBuffer, clBufferIncrement, lRet

            InternetGetText = InternetGetText & Left$(sBuffer, lRet)

        Loop While lRet = clBufferIncrement

    Else

        'Read the specified number of bytes from the file

        InternetReadFile lhFile, sBuffer, lBufferSize, lRet

        InternetGetText = InternetGetText & Left$(sBuffer, lRet)

    End If

    'clean up

    InternetCloseHandle lhFile

    InternetCloseHandle lhOpen

End Function



'Demonstration routine

'(Note the Debug window will only show the last 255 lines)

Sub Test()

    Dim sInterPage As String

    sInterPage = InternetGetText("http://example")

    Debug.Print sInterPage

End Sub