在很多的电脑刊物开发技巧栏目上介绍的判断是否连接到Internet是采取读取注册表的方法来进行的。其实 保存在注册表中的只是本机是否通过RAS连接到远端计算机，该方法只在Windows 9X下和通过Modem上网时才有效 如果是通过局域网或者在NT下连接到Internet，上面的方法就不起作用了。下面的程序通过调用Windows API函数 来获得是否连接到Internet上以及是使用什么方式连接的。 首先建立一个新的VB工程，在Form1中假如一个TextBox控件，然后在Form1的代码窗口中加入以下代码：Dim eR As EIGCInternetConnectionState Dim sMsg As String Dim sName As String Dim bConnected As BooleanPrivate Declare Function InternetGetConnectedStateEx Lib "wininet.dll" _ Alias "InternetGetConnectedStateExA" _ (ByRef lpdwFlags As Long, _ ByVal lpszConnectionName As String, _ ByVal dwNameLen As Long, _ ByVal dwReserved As Long _ ) As LongPrivate Enum EIGCInternetConnectionState INTERNET_CONNECTION_MODEM = &H1& INTERNET_CONNECTION_LAN = &H2& INTERNET_CONNECTION_PROXY = &H4& INTERNET_RAS_INSTALLED = &H10& INTERNET_CONNECTION_OFFLINE = &H20& INTERNET_CONNECTION_CONFIGURED = &H40& End EnumPrivate Function InternetConnected(Optional ByRef eConnectionInfo _ As EIGCInternetConnectionState, Optional ByRef _ sConnectionName As String) As Boolean
Dim dwFlags As Long Dim sNameBuf As String Dim lR As Long Dim iPos As Long
sNameBuf = String$(513, 0) lR = InternetGetConnectedStateEx(dwFlags, sNameBuf, 512, 0&) eConnectionInfo = dwFlags iPos = InStr(sNameBuf, vbNullChar) If iPos > 0 Then sConnectionName = Left$(sNameBuf, iPos - 1) ElseIf Not sNameBuf = String$(513, 0) Then sConnectionName = sNameBuf End If InternetConnected = (lR = 1) End FunctionPrivate Sub Form_Load() '检测是否已经以及使用什么方法连接到Internet bConnected = InternetConnected(eR, sName) '根据获得的结果输出 If (eR And INTERNET_CONNECTION_MODEM) = INTERNET_CONNECTION_MODEM Then sMsg = sMsg & "使用modem连接到Internet." & vbCrLf End If If (eR And INTERNET_CONNECTION_LAN) = INTERNET_CONNECTION_LAN Then sMsg = sMsg & "使用内部网连接到Internet." & vbCrLf End If If (eR And INTERNET_CONNECTION_PROXY) = INTERNET_CONNECTION_PROXY Then sMsg = sMsg & "通过代理服务器连接到Internet." & vbCrLf End If If (eR And INTERNET_CONNECTION_OFFLINE) = INTERNET_CONNECTION_OFFLINE Then sMsg = sMsg & "现在连接处于离线状态." & vbCrLf End If If (eR And INTERNET_CONNECTION_CONFIGURED) = INTERNET_CONNECTION_CONFIGURED Then sMsg = sMsg & "连接已经被设定." & vbCrLf Else sMsg = sMsg & "没有设定好的连接." & vbCrLf End If If (eR And INTERNET_RAS_INSTALLED) = INTERNET_RAS_INSTALLED Then sMsg = sMsg & "本机已经安装了远程访问服务功能." & vbCrLf End If
'显示连接名称 If bConnected Then Text1.Text = "已连接到Internet,连接名称: " & sName & vbCrLf & vbCrLf & sMsg Else Text1.Text = "没有连接到Internet,连接名称: " & sName & vbCrLf & vbCrLf & sMsg End If End Sub 运行程序，可以看到在TextBox框内不仅显示是否连接到Internet，还显示出来使用什么方式连接以及建立 连接的名称。
IP检测如下：模块 Option Explicit Public Const IP_STATUS_BASE = 11000 Public Const IP_SUCCESS = 0 Public Const IP_BUF_TOO_SMALL = (11000 + 1) Public Const IP_DEST_NET_UNREACHABLE = (11000 + 2) Public Const IP_DEST_HOST_UNREACHABLE = (11000 + 3) Public Const IP_DEST_PROT_UNREACHABLE = (11000 + 4) Public Const IP_DEST_PORT_UNREACHABLE = (11000 + 5) Public Const IP_NO_RESOURCES = (11000 + 6) Public Const IP_BAD_OPTION = (11000 + 7) Public Const IP_HW_ERROR = (11000 + 8) Public Const IP_PACKET_TOO_BIG = (11000 + 9) Public Const IP_REQ_TIMED_OUT = (11000 + 10) Public Const IP_BAD_REQ = (11000 + 11) Public Const IP_BAD_ROUTE = (11000 + 12) Public Const IP_TTL_EXPIRED_TRANSIT = (11000 + 13) Public Const IP_TTL_EXPIRED_REASSEM = (11000 + 14) Public Const IP_PARAM_PROBLEM = (11000 + 15) Public Const IP_SOURCE_QUENCH = (11000 + 16) Public Const IP_OPTION_TOO_BIG = (11000 + 17) Public Const IP_BAD_DESTINATION = (11000 + 18) Public Const IP_ADDR_DELETED = (11000 + 19) Public Const IP_SPEC_MTU_CHANGE = (11000 + 20) Public Const IP_MTU_CHANGE = (11000 + 21) Public Const IP_UNLOAD = (11000 + 22) Public Const IP_ADDR_ADDED = (11000 + 23) Public Const IP_GENERAL_FAILURE = (11000 + 50) Public Const MAX_IP_STATUS = 11000 + 50 Public Const IP_PENDING = (11000 + 255) Public Const PING_TIMEOUT = 200 Public Const WS_VERSION_REQD = &H101 Public Const WS_VERSION_MAJOR = WS_VERSION_REQD \ &H100 And &HFF& Public Const WS_VERSION_MINOR = WS_VERSION_REQD And &HFF& Public Const MIN_SOCKETS_REQD = 1 Public Const SOCKET_ERROR = -1 Public Const MAX_WSADescription = 256 Public Const MAX_WSASYSStatus = 128Public Type ICMP_OPTIONS Ttl As Byte Tos As Byte Flags As Byte OptionsSize As Byte OptionsData As Long End TypeDim ICMPOPT As ICMP_OPTIONSPublic Type ICMP_ECHO_REPLY Address As Long status As Long RoundTripTime As Long DataSize As Integer Reserved As Integer DataPointer As Long Options As ICMP_OPTIONS Data As String * 250 End TypePublic Type HOSTENT hName As Long hAliases As Long hAddrType As Integer hLen As Integer hAddrList As Long End TypePublic Type WSADATA wVersion As Integer wHighVersion As Integer szDescription(0 To MAX_WSADescription) As Byte szSystemStatus(0 To MAX_WSASYSStatus) As Byte wMaxSockets As Integer wMaxUDPDG As Integer dwVendorInfo As Long End TypePublic Declare Function IcmpCreateFile Lib "icmp.dll" () As Long Public Declare Function IcmpCloseHandle Lib "icmp.dll" _ (ByVal IcmpHandle As Long) As Long Public Declare Function IcmpSendEcho Lib "icmp.dll" _ (ByVal IcmpHandle As Long, _ ByVal DestinationAddress As Long, _ ByVal RequestData As String, _ ByVal RequestSize As Integer, _ ByVal RequestOptions As Long, _ ReplyBuffer As ICMP_ECHO_REPLY, _ ByVal ReplySize As Long, _ ByVal Timeout As Long) As LongPublic Declare Function WSAGetLastError Lib "WSOCK32.DLL" () As Long Public Declare Function WSAStartup Lib "WSOCK32.DLL" _ (ByVal wVersionRequired As Long, _ lpWSADATA As WSADATA) As Long Public Declare Function WSACleanup Lib "WSOCK32.DLL" () As Long Public Declare Function gethostname Lib "WSOCK32.DLL" _ (ByVal szHost As String, _ ByVal dwHostLen As Long) As Long Public Declare Function gethostbyname Lib "WSOCK32.DLL" _ (ByVal szHost As String) As Long Public Declare Sub RtlMoveMemory Lib "kernel32" _ (hpvDest As Any, _ ByVal hpvSource As Long, _ ByVal cbCopy As Long)
Public Function GetStatusCode(status As Long) As String Dim msg As String Select Case status Case IP_SUCCESS: msg = "ip success" Case IP_BUF_TOO_SMALL: msg = "ip buf too_small" Case IP_DEST_NET_UNREACHABLE: msg = "ip dest net unreachable" Case IP_DEST_HOST_UNREACHABLE: msg = "ip dest host unreachable" Case IP_DEST_PROT_UNREACHABLE: msg = "ip dest prot unreachable" Case IP_DEST_PORT_UNREACHABLE: msg = "ip dest port unreachable" Case IP_NO_RESOURCES: msg = "ip no resources" Case IP_BAD_OPTION: msg = "ip bad option" Case IP_HW_ERROR: msg = "ip hw_error" Case IP_PACKET_TOO_BIG: msg = "ip packet too_big" Case IP_REQ_TIMED_OUT: msg = "ip req timed out" Case IP_BAD_REQ: msg = "ip bad req" Case IP_BAD_ROUTE: msg = "ip bad route" Case IP_TTL_EXPIRED_TRANSIT: msg = "ip ttl expired transit" Case IP_TTL_EXPIRED_REASSEM: msg = "ip ttl expired reassem" Case IP_PARAM_PROBLEM: msg = "ip param_problem" Case IP_SOURCE_QUENCH: msg = "ip source quench" Case IP_OPTION_TOO_BIG: msg = "ip option too_big" Case IP_BAD_DESTINATION: msg = "ip bad destination" Case IP_ADDR_DELETED: msg = "ip addr deleted" Case IP_SPEC_MTU_CHANGE: msg = "ip spec mtu change" Case IP_MTU_CHANGE: msg = "ip mtu_change" Case IP_UNLOAD: msg = "ip unload" Case IP_ADDR_ADDED: msg = "ip addr added" Case IP_GENERAL_FAILURE: msg = "ip general failure" Case IP_PENDING: msg = "ip pending" Case PING_TIMEOUT: msg = "ping timeout" Case Else: msg = "unknown msg returned" End Select
GetStatusCode = CStr(status) & " [ " & msg & " ]" End FunctionPublic Function HiByte(ByVal wParam As Integer) HiByte = wParam \ &H100 And &HFF& End FunctionPublic Function LoByte(ByVal wParam As Integer) LoByte = wParam And &HFF& End FunctionPublic Function Ping(szAddress As String, ECHO As ICMP_ECHO_REPLY) As Long Dim hPort As Long Dim dwAddress As Long Dim sDataToSend As String Dim iOpt As Long sDataToSend = "Echo This" dwAddress = AddressStringToLong(szAddress) Call SocketsInitialize hPort = IcmpCreateFile()If IcmpSendEcho(hPort, _ dwAddress, _ sDataToSend, _ Len(sDataToSend), _ 0, _ ECHO, _ Len(ECHO), _ PING_TIMEOUT) Then'the ping succeeded, '.Status will be 0 '.RoundTripTime is the time in ms for 'the ping to complete, '.Data is the data returned (NULL terminated) '.Address is the Ip address that actually replied '.DataSize is the size of the string in .Data Ping = ECHO.RoundTripTime Else: Ping = ECHO.status * -1 End IfCall IcmpCloseHandle(hPort) Call SocketsCleanup End FunctionFunction AddressStringToLong(ByVal tmp As String) As Long Dim i As Integer Dim parts(1 To 4) As String i = 0'we have to extract each part of the '123.456.789.123 string, delimited by 'a periodWhile InStr(tmp, ".") > 0 i = i + 1 parts(i) = Mid(tmp, 1, InStr(tmp, ".") - 1) tmp = Mid(tmp, InStr(tmp, ".") + 1) Wendi = i + 1 parts(i) = tmp If i <> 4 Then AddressStringToLong = 0 Exit Function End If'build the long value out of the 'hex of the extracted strings AddressStringToLong = Val("&H" & Right("00" & Hex(parts(4)), 2) & _ Right("00" & Hex(parts(3)), 2) & _ Right("00" & Hex(parts(2)), 2) & _ Right("00" & Hex(parts(1)), 2)) End FunctionPublic Function SocketsCleanup() As Boolean Dim X As Long X = WSACleanup() If X <> 0 Then MsgBox "Windows Sockets error " & Trim$(Str$(X)) & _ " occurred in Cleanup.", vbExclamation SocketsCleanup = False Else SocketsCleanup = True End If End FunctionPublic Function SocketsInitialize() As Boolean Dim WSAD As WSADATA Dim X As Integer Dim szLoByte As String, szHiByte As String, szBuf As String X = WSAStartup(WS_VERSION_REQD, WSAD) If X <> 0 Then MsgBox "Windows Sockets for 32 bit Windows " & _ "environments is not successfully responding." SocketsInitialize = False Exit Function End IfIf LoByte(WSAD.wVersion) < WS_VERSION_MAJOR Or _ (LoByte(WSAD.wVersion) = WS_VERSION_MAJOR And _ HiByte(WSAD.wVersion) < WS_VERSION_MINOR) ThenszHiByte = Trim$(Str$(HiByte(WSAD.wVersion))) szLoByte = Trim$(Str$(LoByte(WSAD.wVersion))) szBuf = "Windows Sockets Version " & szLoByte & "." & szHiByte szBuf = szBuf & " is not supported by Windows " & _ "Sockets for 32 bit Windows environments." MsgBox szBuf, vbExclamation SocketsInitialize = False Exit FunctionEnd IfIf WSAD.wMaxSockets < MIN_SOCKETS_REQD Then szBuf = "This application requires a minimum of " & _ Trim$(Str$(MIN_SOCKETS_REQD)) & " supported sockets." MsgBox szBuf, vbExclamation SocketsInitialize = False Exit Function End If SocketsInitialize = True End Function窗体 Option ExplicitPrivate Sub Command1_Click()
Dim ECHO As ICMP_ECHO_REPLY Dim pos As Integer Dim ipaddr As String
'ping an ip address, passing the 'address and the ECHO structure ipaddr = InputBox("Input the IP address to ping:", , "127.0.0.1") Call Ping(ipaddr, ECHO) Me.Caption = "Ping - " & ipaddr 'display the results from the ECHO structure Text1(0) = GetStatusCode(ECHO.status) Text1(1) = ECHO.Address Text1(2) = ECHO.RoundTripTime & " ms" Text1(3) = ECHO.DataSize & " bytes"
If Left$(ECHO.Data, 1) <> Chr$(0) Then pos = InStr(ECHO.Data, Chr$(0)) Text1(4) = Left$(ECHO.Data, pos - 1) End If Text1(5) = ECHO.DataPointer
保存在注册表中的只是本机是否通过RAS连接到远端计算机，该方法只在Windows 9X下和通过Modem上网时才有效
如果是通过局域网或者在NT下连接到Internet，上面的方法就不起作用了。下面的程序通过调用Windows API函数
来获得是否连接到Internet上以及是使用什么方式连接的。
首先建立一个新的VB工程，在Form1中假如一个TextBox控件，然后在Form1的代码窗口中加入以下代码：Dim eR As EIGCInternetConnectionState
Dim sMsg As String
Dim sName As String
Dim bConnected As BooleanPrivate Declare Function InternetGetConnectedStateEx Lib "wininet.dll" _
Alias "InternetGetConnectedStateExA" _
(ByRef lpdwFlags As Long, _
ByVal lpszConnectionName As String, _
ByVal dwNameLen As Long, _
ByVal dwReserved As Long _
) As LongPrivate Enum EIGCInternetConnectionState
INTERNET_CONNECTION_MODEM = &H1&
INTERNET_CONNECTION_LAN = &H2&
INTERNET_CONNECTION_PROXY = &H4&
INTERNET_RAS_INSTALLED = &H10&
INTERNET_CONNECTION_OFFLINE = &H20&
INTERNET_CONNECTION_CONFIGURED = &H40&
End EnumPrivate Function InternetConnected(Optional ByRef eConnectionInfo _
As EIGCInternetConnectionState, Optional ByRef _
sConnectionName As String) As Boolean
Dim dwFlags As Long
Dim sNameBuf As String
Dim lR As Long
Dim iPos As Long
sNameBuf = String$(513, 0)
lR = InternetGetConnectedStateEx(dwFlags, sNameBuf, 512, 0&)
eConnectionInfo = dwFlags
iPos = InStr(sNameBuf, vbNullChar)
If iPos > 0 Then
sConnectionName = Left$(sNameBuf, iPos - 1)
ElseIf Not sNameBuf = String$(513, 0) Then
sConnectionName = sNameBuf
End If
InternetConnected = (lR = 1)
End FunctionPrivate Sub Form_Load()
'检测是否已经以及使用什么方法连接到Internet
bConnected = InternetConnected(eR, sName) '根据获得的结果输出
If (eR And INTERNET_CONNECTION_MODEM) = INTERNET_CONNECTION_MODEM Then
sMsg = sMsg & "使用modem连接到Internet." & vbCrLf
End If
If (eR And INTERNET_CONNECTION_LAN) = INTERNET_CONNECTION_LAN Then
sMsg = sMsg & "使用内部网连接到Internet." & vbCrLf
End If
If (eR And INTERNET_CONNECTION_PROXY) = INTERNET_CONNECTION_PROXY Then
sMsg = sMsg & "通过代理服务器连接到Internet." & vbCrLf
End If
If (eR And INTERNET_CONNECTION_OFFLINE) = INTERNET_CONNECTION_OFFLINE Then
sMsg = sMsg & "现在连接处于离线状态." & vbCrLf
End If
If (eR And INTERNET_CONNECTION_CONFIGURED) = INTERNET_CONNECTION_CONFIGURED Then
sMsg = sMsg & "连接已经被设定." & vbCrLf
Else
sMsg = sMsg & "没有设定好的连接." & vbCrLf
End If
If (eR And INTERNET_RAS_INSTALLED) = INTERNET_RAS_INSTALLED Then
sMsg = sMsg & "本机已经安装了远程访问服务功能." & vbCrLf
End If
'显示连接名称
If bConnected Then
Text1.Text = "已连接到Internet,连接名称: " & sName & vbCrLf & vbCrLf & sMsg
Else
Text1.Text = "没有连接到Internet,连接名称: " & sName & vbCrLf & vbCrLf & sMsg
End If
End Sub 运行程序，可以看到在TextBox框内不仅显示是否连接到Internet，还显示出来使用什么方式连接以及建立
连接的名称。
Option Explicit
Public Const IP_STATUS_BASE = 11000
Public Const IP_SUCCESS = 0
Public Const IP_BUF_TOO_SMALL = (11000 + 1)
Public Const IP_DEST_NET_UNREACHABLE = (11000 + 2)
Public Const IP_DEST_HOST_UNREACHABLE = (11000 + 3)
Public Const IP_DEST_PROT_UNREACHABLE = (11000 + 4)
Public Const IP_DEST_PORT_UNREACHABLE = (11000 + 5)
Public Const IP_NO_RESOURCES = (11000 + 6)
Public Const IP_BAD_OPTION = (11000 + 7)
Public Const IP_HW_ERROR = (11000 + 8)
Public Const IP_PACKET_TOO_BIG = (11000 + 9)
Public Const IP_REQ_TIMED_OUT = (11000 + 10)
Public Const IP_BAD_REQ = (11000 + 11)
Public Const IP_BAD_ROUTE = (11000 + 12)
Public Const IP_TTL_EXPIRED_TRANSIT = (11000 + 13)
Public Const IP_TTL_EXPIRED_REASSEM = (11000 + 14)
Public Const IP_PARAM_PROBLEM = (11000 + 15)
Public Const IP_SOURCE_QUENCH = (11000 + 16)
Public Const IP_OPTION_TOO_BIG = (11000 + 17)
Public Const IP_BAD_DESTINATION = (11000 + 18)
Public Const IP_ADDR_DELETED = (11000 + 19)
Public Const IP_SPEC_MTU_CHANGE = (11000 + 20)
Public Const IP_MTU_CHANGE = (11000 + 21)
Public Const IP_UNLOAD = (11000 + 22)
Public Const IP_ADDR_ADDED = (11000 + 23)
Public Const IP_GENERAL_FAILURE = (11000 + 50)
Public Const MAX_IP_STATUS = 11000 + 50
Public Const IP_PENDING = (11000 + 255)
Public Const PING_TIMEOUT = 200
Public Const WS_VERSION_REQD = &H101
Public Const WS_VERSION_MAJOR = WS_VERSION_REQD \ &H100 And &HFF&
Public Const WS_VERSION_MINOR = WS_VERSION_REQD And &HFF&
Public Const MIN_SOCKETS_REQD = 1
Public Const SOCKET_ERROR = -1
Public Const MAX_WSADescription = 256
Public Const MAX_WSASYSStatus = 128Public Type ICMP_OPTIONS
Ttl As Byte
Tos As Byte
Flags As Byte
OptionsSize As Byte
OptionsData As Long
End TypeDim ICMPOPT As ICMP_OPTIONSPublic Type ICMP_ECHO_REPLY
Address As Long
status As Long
RoundTripTime As Long
DataSize As Integer
Reserved As Integer
DataPointer As Long
Options As ICMP_OPTIONS
Data As String * 250
End TypePublic Type HOSTENT
hName As Long
hAliases As Long
hAddrType As Integer
hLen As Integer
hAddrList As Long
End TypePublic Type WSADATA
wVersion As Integer
wHighVersion As Integer
szDescription(0 To MAX_WSADescription) As Byte
szSystemStatus(0 To MAX_WSASYSStatus) As Byte
wMaxSockets As Integer
wMaxUDPDG As Integer
dwVendorInfo As Long
End TypePublic Declare Function IcmpCreateFile Lib "icmp.dll" () As Long
Public Declare Function IcmpCloseHandle Lib "icmp.dll" _
(ByVal IcmpHandle As Long) As Long
Public Declare Function IcmpSendEcho Lib "icmp.dll" _
(ByVal IcmpHandle As Long, _
ByVal DestinationAddress As Long, _
ByVal RequestData As String, _
ByVal RequestSize As Integer, _
ByVal RequestOptions As Long, _
ReplyBuffer As ICMP_ECHO_REPLY, _
ByVal ReplySize As Long, _
ByVal Timeout As Long) As LongPublic Declare Function WSAGetLastError Lib "WSOCK32.DLL" () As Long
Public Declare Function WSAStartup Lib "WSOCK32.DLL" _
(ByVal wVersionRequired As Long, _
lpWSADATA As WSADATA) As Long
Public Declare Function WSACleanup Lib "WSOCK32.DLL" () As Long
Public Declare Function gethostname Lib "WSOCK32.DLL" _
(ByVal szHost As String, _
ByVal dwHostLen As Long) As Long
Public Declare Function gethostbyname Lib "WSOCK32.DLL" _
(ByVal szHost As String) As Long
Public Declare Sub RtlMoveMemory Lib "kernel32" _
(hpvDest As Any, _
ByVal hpvSource As Long, _
ByVal cbCopy As Long)
Dim msg As String
Select Case status
Case IP_SUCCESS: msg = "ip success"
Case IP_BUF_TOO_SMALL: msg = "ip buf too_small"
Case IP_DEST_NET_UNREACHABLE: msg = "ip dest net unreachable"
Case IP_DEST_HOST_UNREACHABLE: msg = "ip dest host unreachable"
Case IP_DEST_PROT_UNREACHABLE: msg = "ip dest prot unreachable"
Case IP_DEST_PORT_UNREACHABLE: msg = "ip dest port unreachable"
Case IP_NO_RESOURCES: msg = "ip no resources"
Case IP_BAD_OPTION: msg = "ip bad option"
Case IP_HW_ERROR: msg = "ip hw_error"
Case IP_PACKET_TOO_BIG: msg = "ip packet too_big"
Case IP_REQ_TIMED_OUT: msg = "ip req timed out"
Case IP_BAD_REQ: msg = "ip bad req"
Case IP_BAD_ROUTE: msg = "ip bad route"
Case IP_TTL_EXPIRED_TRANSIT: msg = "ip ttl expired transit"
Case IP_TTL_EXPIRED_REASSEM: msg = "ip ttl expired reassem"
Case IP_PARAM_PROBLEM: msg = "ip param_problem"
Case IP_SOURCE_QUENCH: msg = "ip source quench"
Case IP_OPTION_TOO_BIG: msg = "ip option too_big"
Case IP_BAD_DESTINATION: msg = "ip bad destination"
Case IP_ADDR_DELETED: msg = "ip addr deleted"
Case IP_SPEC_MTU_CHANGE: msg = "ip spec mtu change"
Case IP_MTU_CHANGE: msg = "ip mtu_change"
Case IP_UNLOAD: msg = "ip unload"
Case IP_ADDR_ADDED: msg = "ip addr added"
Case IP_GENERAL_FAILURE: msg = "ip general failure"
Case IP_PENDING: msg = "ip pending"
Case PING_TIMEOUT: msg = "ping timeout"
Case Else: msg = "unknown msg returned"
End Select
GetStatusCode = CStr(status) & " [ " & msg & " ]"
End FunctionPublic Function HiByte(ByVal wParam As Integer)
HiByte = wParam \ &H100 And &HFF&
End FunctionPublic Function LoByte(ByVal wParam As Integer)
LoByte = wParam And &HFF&
End FunctionPublic Function Ping(szAddress As String, ECHO As ICMP_ECHO_REPLY) As Long
Dim hPort As Long
Dim dwAddress As Long
Dim sDataToSend As String
Dim iOpt As Long
sDataToSend = "Echo This"
dwAddress = AddressStringToLong(szAddress)
Call SocketsInitialize
hPort = IcmpCreateFile()If IcmpSendEcho(hPort, _
dwAddress, _
sDataToSend, _
Len(sDataToSend), _
0, _
ECHO, _
Len(ECHO), _
PING_TIMEOUT) Then'the ping succeeded,
'.Status will be 0
'.RoundTripTime is the time in ms for
'the ping to complete,
'.Data is the data returned (NULL terminated)
'.Address is the Ip address that actually replied
'.DataSize is the size of the string in .Data
Ping = ECHO.RoundTripTime
Else: Ping = ECHO.status * -1
End IfCall IcmpCloseHandle(hPort)
Call SocketsCleanup
End FunctionFunction AddressStringToLong(ByVal tmp As String) As Long
Dim i As Integer
Dim parts(1 To 4) As String
i = 0'we have to extract each part of the
'123.456.789.123 string, delimited by
'a periodWhile InStr(tmp, ".") > 0
i = i + 1
parts(i) = Mid(tmp, 1, InStr(tmp, ".") - 1)
tmp = Mid(tmp, InStr(tmp, ".") + 1)
Wendi = i + 1
parts(i) = tmp
If i <> 4 Then
AddressStringToLong = 0
Exit Function
End If'build the long value out of the
'hex of the extracted strings
AddressStringToLong = Val("&H" & Right("00" & Hex(parts(4)), 2) & _
Right("00" & Hex(parts(3)), 2) & _
Right("00" & Hex(parts(2)), 2) & _
Right("00" & Hex(parts(1)), 2))
End FunctionPublic Function SocketsCleanup() As Boolean
Dim X As Long
X = WSACleanup()
If X <> 0 Then
MsgBox "Windows Sockets error " & Trim$(Str$(X)) & _
" occurred in Cleanup.", vbExclamation
SocketsCleanup = False
Else
SocketsCleanup = True
End If
End FunctionPublic Function SocketsInitialize() As Boolean
Dim WSAD As WSADATA
Dim X As Integer
Dim szLoByte As String, szHiByte As String, szBuf As String
X = WSAStartup(WS_VERSION_REQD, WSAD)
If X <> 0 Then
MsgBox "Windows Sockets for 32 bit Windows " & _
"environments is not successfully responding."
SocketsInitialize = False
Exit Function
End IfIf LoByte(WSAD.wVersion) < WS_VERSION_MAJOR Or _
(LoByte(WSAD.wVersion) = WS_VERSION_MAJOR And _
HiByte(WSAD.wVersion) < WS_VERSION_MINOR) ThenszHiByte = Trim$(Str$(HiByte(WSAD.wVersion)))
szLoByte = Trim$(Str$(LoByte(WSAD.wVersion)))
szBuf = "Windows Sockets Version " & szLoByte & "." & szHiByte
szBuf = szBuf & " is not supported by Windows " & _
"Sockets for 32 bit Windows environments."
MsgBox szBuf, vbExclamation
SocketsInitialize = False
Exit FunctionEnd IfIf WSAD.wMaxSockets < MIN_SOCKETS_REQD Then
szBuf = "This application requires a minimum of " & _
Trim$(Str$(MIN_SOCKETS_REQD)) & " supported sockets."
MsgBox szBuf, vbExclamation
SocketsInitialize = False
Exit Function
End If
SocketsInitialize = True
End Function窗体
Option ExplicitPrivate Sub Command1_Click()
Dim ECHO As ICMP_ECHO_REPLY
Dim pos As Integer
Dim ipaddr As String
'ping an ip address, passing the
'address and the ECHO structure
ipaddr = InputBox("Input the IP address to ping:", , "127.0.0.1")
Call Ping(ipaddr, ECHO)
Me.Caption = "Ping - " & ipaddr
'display the results from the ECHO structure
Text1(0) = GetStatusCode(ECHO.status)
Text1(1) = ECHO.Address
Text1(2) = ECHO.RoundTripTime & " ms"
Text1(3) = ECHO.DataSize & " bytes"
If Left$(ECHO.Data, 1) <> Chr$(0) Then
pos = InStr(ECHO.Data, Chr$(0))
Text1(4) = Left$(ECHO.Data, pos - 1)
End If Text1(5) = ECHO.DataPointer
End Sub