如何用代码实现PING命令？

chenwintek

也就是说用代码获取某IP地址是否连通？

zhuyiwen

转自:http://www.mvps.org/access/api/api0067.htm


API: Perform IP Lookups and resolve addresses


Windows Sockets API functions allow us to return low level information about various network related items. By using the gethostbyname and gethostbyaddr API functions, we can resolve or look up IP addresses.

  Since a machine can have multiple IP addresses bound to it, a call to fGetHostIPAddresses will return a VBA collection filled with all the possible IP addresses.  A call to fGetHostName will return only one IP address since IP Addresses will be unique.

Usage Samples:

IP Lookup:
   ?fGetHostIPAddresses("machineName").Item(1)
   192.0.09.121  ' Bogus IP listed here
Name resolution:
  ?fGetHostName("192.0.09.121")
  machineName

' ******** Code Start ********
'This code was originally written by Dev Ashish.
'It is not to be altered or distributed,
'except as part of an application.
'You are free to use it in any application,
'provided the copyright notice is left unchanged.
'
'Code Courtesy of
'Dev Ashish
'
Private Const MAX_WSADescription = 256
Private Const MAX_WSASYSStatus = 128
Private Const AF_INET = 2

Private Type WSADATA
    wversion As Integer
    wHighVersion As Integer
    szDescription(MAX_WSADescription) As Byte
    szSystemStatus(MAX_WSASYSStatus) As Byte
    wMaxSockets As Long
    wMaxUDPDG As Long
    dwVendorInfo As Long
End Type
  
Private Type HOSTENT
    hName As Long
    hAliases As Long
    hAddrType As Integer
    hLength As Integer
    hAddrList As Long
End Type

' returns the standard host name for the local machine
Private Declare Function apiGetHostName _
    Lib "wsock32" Alias "gethostname" _
    (ByVal name As String, _
    ByVal nameLen As Long) _
    As Long

' retrieves host information corresponding to a host name
' from a host database
Private Declare Function apiGetHostByName _
    Lib "wsock32" Alias "gethostbyname" _
    (ByVal hostname As String) _
    As Long

' retrieves the host information corresponding to a network address
Private Declare Function apiGetHostByAddress _
    Lib "wsock32" Alias "gethostbyaddr" _
    (addr As Long, _
    ByVal dwLen As Long, _
    ByVal dwType As Long) _
    As Long

' moves memory either forward or backward, aligned or unaligned,
' in 4-byte blocks, followed by any remaining bytes
Private Declare Sub sapiCopyMem _
    Lib "kernel32" Alias "RtlMoveMemory" _
    (Destination As Any, _
    Source As Any, _
    ByVal Length As Long)

' converts a string containing an (Ipv4) Internet Protocol
' dotted address into a proper address for the IN_ADDR structure
Private Declare Function apiInetAddress _
    Lib "wsock32" Alias "inet_addr" _
    (ByVal cp As String) _
    As Long

' function initiates use of Ws2_32.dll by a process
Private Declare Function apiWSAStartup _
    Lib "wsock32" Alias "WSAStartup" _
    (ByVal wVersionRequired As Integer, _
    lpWsaData As WSADATA) _
    As Long

Private Declare Function apilstrlen _
    Lib "kernel32" Alias "lstrlen" _
    (ByVal lpString As Long) _
    As Long

Private Declare Function apilstrlenW _
    Lib "kernel32" Alias "lstrlenW" _
    (ByVal lpString As Long) _
    As Long

' function terminates use of the Ws2_32.dll
Private Declare Function apiWSACleanup _
    Lib "wsock32" Alias "WSACleanup" _
    () As Long
   
Function fGetHostIPAddresses(strHostName As String) As Collection
'
' Resolves the English HostName and returns
' a collection with all the IPs bound to the card
'
On Error GoTo ErrHandler
Dim lngRet As Long
Dim lpHostEnt As HOSTENT
Dim strOut As String
Dim colOut As Collection
Dim lngIPAddr As Long
Dim abytIPs() As Byte
Dim i As Integer

    Set colOut = New Collection
   
    If fInitializeSockets() Then
        strOut = String$(255, vbNullChar)
        lngRet = apiGetHostByName(strHostName)
        If lngRet Then
        
            Call sapiCopyMem( _
                    lpHostEnt, _
                    ByVal lngRet, _
                    Len(lpHo

zhuyiwen

我想在局域网中,如果能通过机器名得到IP地址,那么网络就应该是通的