form1.frm

电子书“Visual Basic 6 网络编程实例教程.rar”

VERSION 5.00
Begin VB.Form Form1 
   BackColor       =   &H00808000&
   BorderStyle     =   1  'Fixed Single
   Caption         =   "网卡的IP地址"
   ClientHeight    =   2010
   ClientLeft      =   45
   ClientTop       =   330
   ClientWidth     =   2985
   Icon            =   "Form1.frx":0000
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   2010
   ScaleWidth      =   2985
   StartUpPosition =   2  '屏幕中心
   Begin VB.TextBox Text1 
      Height          =   375
      Left            =   720
      TabIndex        =   1
      Text            =   "Text1"
      Top             =   720
      Width           =   1575
   End
   Begin VB.CommandButton Command1 
      Caption         =   "运行(&R)"
      Default         =   -1  'True
      Height          =   375
      Left            =   960
      TabIndex        =   0
      Top             =   1440
      Width           =   1095
   End
   Begin VB.Label Label1 
      AutoSize        =   -1  'True
      BackStyle       =   0  'Transparent
      Caption         =   "网卡的本地IP地址"
      Height          =   180
      Left            =   720
      TabIndex        =   2
      Top             =   480
      Width           =   1440
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

Private Sub Command1_Click()
    Text1.Text = LocalIPAddress()
End Sub

Private Function LocalIPAddress() As String
   Dim cbRequired  As Long
   Dim buff()      As Byte
   Dim Adapter     As IP_ADAPTER_INFO
   Dim AdapterStr  As IP_ADDR_STRING
   Dim ptr1        As Long
   Dim sIPAddr     As String
   Dim found       As Boolean
   Call GetAdaptersInfo(ByVal 0&, cbRequired)
   If cbRequired > 0 Then
      ReDim buff(0 To cbRequired - 1) As Byte
      If GetAdaptersInfo(buff(0), cbRequired) = ERROR_SUCCESS Then
        '获取存放在buff()中的数据的指针
         ptr1 = VarPtr(buff(0))
         Do While (ptr1 <> 0)
           '将第一个网卡的数据转换到IP_ADAPTER_INFO结构中
            CopyMemory Adapter, ByVal ptr1, LenB(Adapter)
            With Adapter
              'IpAddress.IpAddr成员给出了DHCP的IP地址
               sIPAddr = TrimNull(StrConv(.IpAddressList.IpAddress.IpAddr, vbUnicode))
               If Len(sIPAddr) > 0 Then
                  found = True
                  Exit Do
               End If
               ptr1 = .dwNext
            End With  'With Adapter
        '不再有网卡时，ptr1的值为0
         Loop  'Do While (ptr1 <> 0)
      End If  'If GetAdaptersInfo
   End If  'If cbRequired > 0
  '返回结果字符串
   LocalIPAddress = sIPAddr
End Function

Private Function TrimNull(item As String)
    Dim pos As Integer
    pos = InStr(item, Chr$(0))
    If pos Then
          TrimNull = Left$(item, pos - 1)
    Else: TrimNull = item
    End If
End Function