首先添加一模块，代码如下
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Option Explicit
Private Const IP_SUCCESS As Long = 0
Private Const IP_STATUS_BASE As Long = 11000
Private Const IP_BUF_TOO_SMALL As Long = (11000 + 1)
Private Const IP_DEST_NET_UNREACHABLE As Long = (11000 + 2)
Private Const IP_DEST_HOST_UNREACHABLE As Long = (11000 + 3)
Private Const IP_DEST_PROT_UNREACHABLE As Long = (11000 + 4)
Private Const IP_DEST_PORT_UNREACHABLE As Long = (11000 + 5)
Private Const IP_NO_RESOURCES As Long = (11000 + 6)
Private Const IP_BAD_OPTION As Long = (11000 + 7)
Private Const IP_HW_ERROR As Long = (11000 + 8)
Private Const IP_PACKET_TOO_BIG As Long = (11000 + 9)
Private Const IP_REQ_TIMED_OUT As Long = (11000 + 10)
Private Const IP_BAD_REQ As Long = (11000 + 11)
Private Const IP_BAD_ROUTE As Long = (11000 + 12)
Private Const IP_TTL_EXPIRED_TRANSIT As Long = (11000 + 13)
Private Const IP_TTL_EXPIRED_REASSEM As Long = (11000 + 14)
Private Const IP_PARAM_PROBLEM As Long = (11000 + 15)
Private Const IP_SOURCE_QUENCH As Long = (11000 + 16)
Private Const IP_OPTION_TOO_BIG As Long = (11000 + 17)
Private Const IP_BAD_DESTINATION As Long = (11000 + 18)
Private Const IP_ADDR_DELETED As Long = (11000 + 19)
Private Const IP_SPEC_MTU_CHANGE As Long = (11000 + 20)
Private Const IP_MTU_CHANGE As Long = (11000 + 21)
Private Const IP_UNLOAD As Long = (11000 + 22)
Private Const IP_ADDR_ADDED As Long = (11000 + 23)
Private Const IP_GENERAL_FAILURE As Long = (11000 + 50)
Private Const MAX_IP_STATUS As Long = (11000 + 50)
Private Const IP_PENDING As Long = (11000 + 255)
Private Const PING_TIMEOUT As Long = 500
Private Const WS_VERSION_REQD As Long = H101
Private Const MIN_SOCKETS_REQD As Long = 1
Private Const SOCKET_ERROR As Long = -1
Private Const INADDR_NONE As Long = HFFFFFFFF
Private Const MAX_WSADescription As Long = 256
Private Const MAX_WSASYSStatus As Long = 128
Public PingTime As Long
Private Type ICMP_OPTIONS
Ttl As Byte
Tos As Byte
Flags As Byte
OptionsSize As Byte
OptionsData As Long
End Type
Private Type ICMP_ECHO_REPLY
Address As Long
status As Long
RoundTripTime As Long
DataSize As Long
DataPointer As Long
Options As ICMP_OPTIONS
Data As String * 250
End Type
Private Type WSADATA
wVersion As Integer
wHighVersion As Integer
szDescription(0 To MAX_WSADescription) As Byte
szSystemStatus(0 To MAX_WSASYSStatus) As Byte
wMaxSockets As Long
wMaxUDPDG As Long
dwVendorInfo As Long
End Type
Public Declare Function timeGetTime Lib "winmm.dll" () As Long
Private Declare Function WSAStartup Lib "wsock32" (ByVal wVersionRequired As Long, lpWSADATA As WSADATA) As Long
Private Declare Function WSACleanup Lib "wsock32" () As Long
Private Declare Function IcmpCreateFile Lib "icmp.dll" () As Long
Private Declare Function inet_addr Lib "wsock32" (ByVal s As String) As Long
Private Declare Function IcmpCloseHandle Lib "icmp.dll" (ByVal IcmpHandle As Long) As Long
Private Declare Function IcmpSendEcho Lib "icmp.dll" (ByVal IcmpHandle As Long, ByVal DestinationAddress As Long, ByVal RequestData As String, ByVal RequestSize As Long, ByVal RequestOptions As Long, ReplyBuffer As ICMP_ECHO_REPLY, ByVal ReplySize As Long, ByVal Timeout As Long) As Long
'Private Declare Function WSAGetLastError Lib "wsock32" () As Long
'Private Declare Function gethostname Lib "wsock32" (ByVal szHost As String, ByVal dwHostLen As Long) As Long
'Private Declare Function gethostbyname Lib "wsock32" (ByVal szHost As String) As Long
'Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (xDest As Any, xSource As Any, ByVal nbytes As Long)
Private Function GetStatusCode(status As Long) As String
On Error GoTo ErrLine
Dim Msg As String
GetStatusCode = ""
Select Case status
Case IP_SUCCESS: Msg = "ip success"
Case INADDR_NONE: Msg = "inet_addr: bad IP format"
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 port 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 = Msg
Exit Function
ErrLine:
End Function
Private Function Ping(sAddress As String, sDataToSend As String, ECHO As ICMP_ECHO_REPLY) As Long
On Error GoTo ErrLine
Dim hPort As Long
Dim dwAddress As Long
dwAddress = inet_addr(sAddress)
If dwAddress INADDR_NONE Then
hPort = IcmpCreateFile()
If hPort Then
Call IcmpSendEcho(hPort, dwAddress, sDataToSend, Len(sDataToSend), 0, ECHO, Len(ECHO), PING_TIMEOUT)
Ping = ECHO.status
Call IcmpCloseHandle(hPort)
End If
Else
Ping = INADDR_NONE
End If
Exit Function
ErrLine:
Ping = INADDR_NONE
End Function
Public Function PingIP(ByVal szIp As String) As Boolean
On Error GoTo ErrLine
Dim WSAD As WSADATA
Dim ECHO As ICMP_ECHO_REPLY
Dim ret As Long
'Delay 150
PingIP = False
PingTime = Empty
If WSAStartup(WS_VERSION_REQD, WSAD) = IP_SUCCESS Then
ret = Ping(Trim(szIp), "tanaya", ECHO)
PingTime = ECHO.RoundTripTime
If InStr(1, GetStatusCode(ret), "success") 0 Then
WSACleanup
PingIP = True
PingTime = ECHO.RoundTripTime
Exit Function
End If
End If
Exit Function
ErrLine:
End Function
然后建立一窗体，一command
Private Sub Command1_Click()
If PingIP("你需要访问的ip") = True Then
'你自己增加需要执行的代码
else
'增加不联网时需要执行的代码
end if
VB添加inet控件步骤：
运行VB6.0，新建工程。
菜单工程-部件，在Microsoft Internet Transfer Control 6.0部件前勾选，确定，就可将Inet控件添加到工具箱。
双击工具箱Inet控件，窗体上就添加了该控件。
Microsoft Internet Transfer 控件：
Internet Transfer 控件支持超文本传输协议 (HTTP) 和文件传输协议 (FTP)，它们是 Internet 网上使用最广泛的两种协议。
使用 HTTP 协议，可以连接全球信息网（World Wide Web）服务器，以检索 HTML 文档。使用 FTP 协议可以在 FTP服务器上登录，以下载和加载文件。UserName 和 Password 属性可让您在要求验证身份的私有的服务器上进行登录。另外，也可以连接公用的 FTP 服务器，并下载文件。Execute 方法支持普通的 FTP
命令，如 CD 和 GET。
'邮件已回，请收.
'在这里也随便说一下,你把你的代码照下面这样改正就OK了．
Private Sub downloadone_Click()
Dim strSite As String, strFile As String, strCommand As String
strSite = ""
strFile = "思科路由器常用配置命令大全.txt"
ftpone.Protocol = icFTP
ftpone.URL = strSite '这里改过,调整了代码顺序,这是必须的
ftpone.UserName = "upload"
ftpone.Password = "upload"
'下面是我改过的代码
strCommand = "Get " "/upload_1/" strFile " D:\" strFile
ftpone.Execute , strCommand
End Sub
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星期一给你答复.
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连接到FTP服务器有两个重要参数!
1.FTP的地址,也即是域名,或者IP地址.
2.端口.一般来说FTP使用21号端口,也有例外.
检查你这两个参数对没有.
你最好ping一个你的FTP地址.
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我晕啊,你自己好好检查你的用户名和密码吧.还要注意用户名的大小写.
哎,你可不可以把你的整个VB工程,打个包发给我看看啊.我帮你改改.
xie_jian_jun@163.com,顺便要说明你的错误现象.
企业版应该有的，用法 工程-----部件-------勾选Microsoft internet transfer control 6.0---应用----确定，工具箱里就会有inet控件。找不到Microsoft internet transfer control 6.0的话，下载msinet.ocx 放到c:\windows\system32\下，注册，然后用法同上
帮你加上注释吧，晕倒... On Error Resume Next '发生错误时继续下一步Inet1.AccessType = 2 '访问类型
Inet1.RequestTimeout = 60 '请求超时
Inet1.Proxy = "HTTP=" "59.74.42.152" ":" "8080" '代理
Inet1.OpenURL (" ") '打开的网址
MsgBox Val(Mid(Trim(Inet1.GetHeader), 10, 3))
If Err Then
If Err.Number = 35756 Then MsgBox "代理不可用"
MsgBox Err.Number ":" Err.Description
End If
End Sub