<p>程式自動呼叫撥號網絡(RAS API) </p>
<p></p>
<p>在RAS API的呼叫上，有許多方要注意，以下便加以說明</p>
<p></p>
<p>在C中宣告成</p>
<p>#Define RAS_MaxEntryName  256;</p>
<p>Struct RASENTRYNAME</p>
<p>{</p>
<p>    DWORD dwSize;</p>
<p>    CHAR  szEntryName[ RAS_MaxEntryName + 1 ];</p>
<p>};</p>
<p></p>
<p>VB 宣告成</p>
<p>Public Const RAS_MaxEntryName = 256</p>
<p></p>
<p>Private Type RASENTRYNAME</p>
<p>  dwSize As Long</p>
<p>  szEntryName(RAS_MaxEntryName) As Byte</p>
<p>End Type</p>
<p></p>
<p>　　c 中 Char aa[16] 代表長度是16，可放 15個byte所以對應於vb便是 aa(15) as Byte</p>
<p>如此才是長度16 ( 0--15)。故VB的宣告中不能再用szEntryName(RAS_MaxEntryName+1)</p>
<p></p>
<p>　　但是Lenb(RASENTRYNAME)的長度卻是 261 (4+257)，的確，這是vb的問題，而c 的SizeOf傳回的是4的倍數(32位元嘛)故值為264，所以我們計算某個Structure的長度時，要再多一些運算。</p>
<p></p>
<p>以下的Fuction只適用於32位元的win95/ NT，</p>
<p></p>
<p>注釋：以下在Form中</p>
<p></p>
<p>Private hConn as Long</p>
<p>Private Sub Command1_Click()</p>
<p>  hConn = Dialup("我的連線", "user", "passwd")</p>
<p>  if hConn = 0 Then</p>
<p>     Debug.Print "連線失敗"</p>
<p>  end if</p>
<p>End Sub</p>
<p></p>
<p>Private Sub Command2_Click()</p>
<p>  Call HangUp(hConn)</p>
<p>End Sub</p>
<p></p>
<p>注釋：以下在.bas中</p>
<p>Option Explicit</p>
<p>  Public Const RAS_MaxEntryName = 256</p>
<p>  Public Const RAS_MaxDeviceName = 128</p>
<p>  Public Const RAS_MaxDeviceType = 16</p>
<p>  Public Const RAS_MaxPhoneNumber = 128</p>
<p>  Public Const RAS_MaxCallbackNumber = 128</p>
<p>  Public Const UNLEN = 256</p>
<p>  Public Const PWLEN = 256</p>
<p>  Public Const DNLEN = 15</p>
<p>  Public Const ERROR_INVALID_HANDLE = 6</p>
<p>Type RASDIALPARAMS</p>
<p>    dwSize As Long 注釋：1052</p>
<p>    szEntryName(RAS_MaxEntryName) As Byte</p>
<p>    szPhoneNumber(RAS_MaxPhoneNumber) As Byte</p>
<p>    szCallbackNumber(RAS_MaxCallbackNumber) As Byte</p>
<p>    szUserName(UNLEN) As Byte</p>
<p>    szPassword(PWLEN) As Byte</p>
<p>    szDomain(DNLEN) As Byte</p>
<p>  End Type</p>
<p></p>
<p>  Type RASCONNSTATUS</p>
<p>      dwSize As Long  注釋：144</p>
<p>      RasConnState As Long</p>
<p>      dwError As Long</p>
<p>      szDeviceType(RAS_MaxDeviceType) As Byte</p>
<p>      szDeviceName(RAS_MaxDeviceName) As Byte</p>
<p>  End Type</p>
<p></p>
<p>  Declare Function RasGetErrorString Lib "rasapi32" _</p>
<p>    Alias "RasGetErrorStringA" (ByVal ErrValue As Long, ByVal lpErrStr As String, _</p>
<p>    ByVal cSize As Long) As Long</p>
<p>  Declare Function RasDial Lib "rasapi32" _</p>
<p>    Alias "RasDialA" (DialExt As Long, ByVal lpPhoneBook As String, _</p>
<p>    RasDialParam As RASDIALPARAMS, ByVal NotifyType As Long, _</p>
<p>    ByVal Notifter As Long, hRasConn As Long) As Long</p>
<p>  Declare Function RasHangUp Lib "rasapi32" Alias _</p>
<p>        "RasHangUpA" (ByVal hRasConn As Long) As Long</p>
<p>  Declare Function RasGetConnectStatus Lib "rasapi32" Alias _</p>
<p>        "RasGetConnectStatusA" (ByVal hRasConn As Long, _</p>
<p>        lprasconnstatus As RASCONNSTATUS) As Long</p>
<p>  Declare Function RasGetEntryDialParams Lib "rasapi32" _</p>
<p>     Alias "RasGetEntryDialParamsA" (ByVal lpszPhonebook As String, _</p>
<p>     lpRasDialParams As RASDIALPARAMS, _</p>
<p>     lpfPassword As Byte) As Long</p>
<p>  Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)</p>
<p></p>
<p>  注釋：自動撥號(Win95 4, 5 個叁數不傳，或為vbNullString)</p>
<p>  Public Function DialUp(ByVal EntryName As String, ByVal UserN As String, _</p>
<p>      ByVal Pwd As String, Optional ByVal PhoneBook As String, Optional sDomain As String) As Long</p>
<p>  Dim RasDialPara As RASDIALPARAMS</p>
<p>  Dim bya() As Byte, di As Long</p>
<p>  Dim len5 As Long, i As Long</p>
<p>  Dim hRasConn As Long</p>
<p></p>
<p>  len5 = LenB(RasDialPara)</p>
<p>  i = (4 - (len5 Mod 4)) Mod 4</p>
<p>  RasDialPara.dwSize = len5 + i 注釋：1052</p>
<p>  bya = StrConv(EntryName, vbFromUnicode) + ChrB(0)</p>
<p>  Call CopyByte(RasDialPara.szEntryName, bya)</p>
<p></p>
<p>  bya = StrConv(UserN, vbFromUnicode) + ChrB(0)</p>
<p>  Call CopyByte(RasDialPara.szUserName, bya)</p>
<p></p>
<p>  bya = StrConv(Pwd, vbFromUnicode) + ChrB(0)</p>
<p>  Call CopyByte(RasDialPara.szPassword, bya)</p>
<p></p>
<p>  bya = StrConv(sDomain, vbFromUnicode) + ChrB(0)</p>
<p>  Call CopyByte(RasDialPara.szDomain, bya)</p>
<p>  注釋：若使用以下CallBack function的方式，則RasDial()不等連線成功或失敗便結束。</p>
<p>  di = RasDial(0, PhoneBook, RasDialPara, 0, AddressOf RasDialFunc, hRasConn)</p>
<p></p>
<p>  注釋：若第二、三個叁數都是0則，RasDial會等連線成功或失敗後才執行下一行指令</p>
<p>  注釋：di = RasDial(0, PhoneBook, RasDialPara, 0, 0, hRasConn)</p>
<p></p>
<p>  If di = 0 Then</p>
<p>     DialUp = hRasConn</p>
<p>  Else</p>
<p>     DialUp = 0</p>
<p>     Dim str5 As String</p>
<p>     str5 = String(255, Chr(0))</p>
<p>     Call RasGetErrorString(di, str5, 256)</p>
<p>     MsgBox Left(str5, InStr(1, str5, Chr(0)) - 1), vbCritical</p>
<p>     Call HangUp(hRasConn)</p>
<p>  End If</p>
<p>  End Function</p>
<p></p>
<p>  Public Sub RasDialFunc(ByVal unMsg As Long, _</p>
<p>                         ByVal ConnState As Long, _</p>
<p>                         ByVal dwError As Long)</p>
<p>  If ConnState = &H2000 Then</p>
<p>     注釋： Connect Complete</p>
<p>  End If</p>
<p></p>
<p>  注釋：取消撥號</p>
<p>  Public Function HangUp(ByVal hconn As Long) As Boolean</p>
<p>  Dim st As Long, len5 As Long</p>
<p>  Dim i As Long, ConStatus  As RASCONNSTATUS</p>
<p>  st = RasHangUp(hconn)</p>
<p>  len5 = LenB(ConStatus)</p>
<p>  i = (4 - (len5 Mod 4)) Mod 4</p>
<p>  ConStatus.dwSize = len5 + i</p>
<p>  Do While True</p>
<p>    Call Sleep(0)</p>
<p>    i = RasGetConnectStatus(hconn, ConStatus)</p>
<p>    If i = ERROR_INVALID_HANDLE Then</p>
<p>       Exit Do</p>
<p>    End If</p>
<p>  Loop</p>
<p>  If st = 0 Then</p>
<p>     HangUp = True</p>
<p>  Else</p>
<p>     HangUp = False</p>
<p>  End If</p>
<p>  End Function</p>
<p></p>
<p>  Private Sub CopyByte(dest() As Byte, sour() As Byte)</p>
<p>  Dim sourL As Long, sourU As Long</p>
<p>  Dim destL As Long, destU As Long, i As Long, j As Long</p>
<p>  sourL = LBound(sour)</p>
<p>  sourU = UBound(sour)</p>
<p>  destL = LBound(dest)</p>
<p>  destU = UBound(dest)</p>
<p>  j = 0</p>
<p>  For i = sourL To sourU</p>
<p>      dest(destL + j) = sour(i)</p>
<p>      j = j + 1</p>
<p>      If j >= (destU - destL) + 1 Then</p>
<p>         Exit For</p>
<p>      End If</p>
<p>  Next i</p>
<p>  End Sub</p>
<p> </p>