DNS Inside Out
Tutorial for the Visual Basic programmer
http://www.vbip.com/protocols/dns/vb-dns-tutorial-01.aspResolving a domain name into an IP address
http://www.vbip.com/protocols/dns/vb-dns-tutorial-12.asp
Tutorial for the Visual Basic programmer
http://www.vbip.com/protocols/dns/vb-dns-tutorial-01.aspResolving a domain name into an IP address
http://www.vbip.com/protocols/dns/vb-dns-tutorial-12.asp
'转自编程先锋 http://wlbookwl.myrice.com 站长:小黑侠
'首先声明是转抄的一篇外国的!
' #VBIDEUtils#************************************************************
' * Programmer Name : Waty Thierry
' * Web Site : www.geocities.com/ResearchTriangle/6311/
' * E-Mail : [email protected]
' * Module Name : IP_Module
' * Module Filename : IP.bas
' **********************************************************************
' * Comments :
' * Find IP address ginving the hostname
' ********************************************************************** 'Here's sample code for gethostbyname() 'Add a textbox (Text1) And a Command button (Command1) To a New form And use the following code: 'Usage: Fill in the textbox with the name you want to resolve and click the command button to resolve the name. Private Const WS_VERSION_REQD = &H101
Private Const WS_VERSION_MAJOR = WS_VERSION_REQD \ &H100 And &HFF&
Private Const WS_VERSION_MINOR = WS_VERSION_REQD And &HFF&
Private Const MIN_SOCKETS_REQD = 1
Private Const SOCKET_ERROR = -1
Private Const WSADescription_Len = 256
Private Const WSASYS_Status_Len = 128 Private Type HOSTENT
hName As Long
hAliases As Long
hAddrType As Integer
hLength As Integer
hAddrList As Long
End Type Private Type WSADATA
wversion As Integer
wHighVersion As Integer
szDescription(0 To WSADescription_Len) As Byte
szSystemStatus(0 To WSASYS_Status_Len) As Byte
iMaxSockets As Integer
iMaxUdpDg As Integer
lpszVendorInfo As Long
End Type Private Declare Function WSAGetLastError Lib "WSOCK32.DLL" () As Long
Private Declare Function WSAStartup Lib "WSOCK32.DLL" (ByVal wVersionRequired&, lpWSAData As WSADATA) As Long
Private Declare Function WSACleanup Lib "WSOCK32.DLL" () As Long
Private Declare Function gethostbyname Lib "WSOCK32.DLL" (ByVal hostname$) As Long
Private Declare Sub RtlMoveMemory Lib "KERNEL32" (hpvDest As Any, ByVal hpvSource&, ByVal cbCopy&) ' #VBIDEUtils#************************************************************
' * Programmer Name : Waty Thierry
' * Web Site : www.geocities.com/ResearchTriangle/6311/
' * E-Mail : [email protected]
' * Module Name : IP_Module
' * Module Filename : IP.bas
' **********************************************************************
' * Comments :
' * Find IP address ginving the hostname
' ********************************************************************** Function hibyte(ByVal wParam As Integer) hibyte = wParam \ &H100 And &HFF& End Function Function lobyte(ByVal wParam As Integer) lobyte = wParam And &HFF& End Function Sub SocketsInitialize() Dim WSAD As WSADATA
Dim iReturn As Integer
Dim sLowByte As String, sHighByte As String, sMsg As String iReturn = WSAStartup(WS_VERSION_REQD, WSAD) If iReturn <> 0 Then
MsgBox "Winsock.dll is not responding."
End
End If If lobyte(WSAD.wversion) < WS_VERSION_MAJOR Or (lobyte(WSAD.wversion) = WS_VERSION_MAJOR And hibyte(WSAD.wversion) < WS_VERSION_MINOR) Then
sHighByte = Trim$(Str$(hibyte(WSAD.wversion)))
sLowByte = Trim$(Str$(lobyte(WSAD.wversion)))
sMsg = "Windows Sockets version " & sLowByte & "." & sHighByte
sMsg = sMsg & " is not supported by winsock.dll "
MsgBox sMsg
End
End If If WSAD.iMaxSockets < MIN_SOCKETS_REQD Then
sMsg = "This application requires a minimum of "
sMsg = sMsg & Trim$(Str$(MIN_SOCKETS_REQD)) & " supported sockets."
MsgBox sMsg
End
End If End Sub Sub SocketsCleanup()
Dim lReturn As Long lReturn = WSACleanup() If lReturn <> 0 Then
MsgBox "Socket error " & Trim$(Str$(lReturn)) & " occurred in Cleanup "
End
End If End Sub Sub Form_Load() SocketsInitialize End Sub Private Sub Form_Unload(Cancel As Integer) SocketsCleanup End Sub Private Sub Command1_click()
Dim hostent_addr As Long
Dim host As HOSTENT
Dim hostip_addr As Long
Dim temp_ip_address() As Byte
Dim i As Integer
Dim ip_address As String hostent_addr = gethostbyname(Text1) If hostent_addr = 0 Then
MsgBox "Can't resolve name."
Exit Sub
End If RtlMoveMemory host, hostent_addr, LenB(host)
RtlMoveMemory hostip_addr, host.hAddrList, 4 ReDim temp_ip_address(1 To host.hLength)
RtlMoveMemory temp_ip_address(1), hostip_addr, host.hLength For i = 1 To host.hLength
ip_address = ip_address & temp_ip_address(i) & "."
Next
ip_address = Mid$(ip_address, 1, Len(ip_address) - 1) MsgBox ip_address End Sub
资料整理:编程先锋 http://wlbookwl.myrice.com 站长:小黑侠