来电显示的实现

MODEM的AT命令CID和VCID是设置是不是来电显示的，如果电信开通了来电显示功能

就能通过MODEM来显示对方的电话号码。那么首先设置CID=1或是VCID=1

般来说来电显示的信息为：

DATE = MMDD "来电日期 MMDD

TIME = HHMM "来电时间 HHMM

NMBR = ######## "来电号码

程序实现如下,设置MSComm1的相关设置，并建两个Label为Label1和Label2

Function OpenCID(OpenCLose As Boolean) As Boolean

'打开或是关毕来电显示功能

  On Error Resume Next

  Dim ArrCID(1) As String

  ArrCID(0) = "at#cid=" & IIf(openclode, 1, 0)

  ArrCID(1) = "at#vcid=" & IIf(openclode, 1, 0)

  MSComm1.RThreshold = 0

  For i = 0 To 1

    MSComm1.Output = ArrCID(i) & vbCr

    EndTime = Timer + 0.5

    Do While bStop = False

      nTemp = nTemp + 1

      If MSComm1.InBufferCount >= 2 Then

        sTemp = MSComm1.Input

        If InStr(sTemp, "OK") = 0 Then

          bStop = True

          OpenCID = True

          Exit Function

        End If

      End If

      If Timer >= EndTime Or ErrorCode Then Exit Do

    Loop

  Next i

  OpenCID = False

  MSComm1.RThreshold = 1

End Function

下面的函数显示来电号码并在窗体上的Label1的Label2上显示出来

Private Sub MSComm1_OnComm()

  On Error Resume Next

  Static Buffer As String

   ' 收到多于 RThreshold 属性设置的字符数（RThreshold 属性必须大于 0）。

      'label1 = "收到" + Str(MSComm1.InBufferCount) + "个字符"

      Buffer = Buffer + MSComm1.Input

      Buffer = UCase(Buffer)

     '  Exit Sub

      If InStr(1, Buffer, "RING", vbTextCompare) Then

      '收到震铃

        'Comm1.Output = "ATA" + Chr(13) '命令 Modem 摘机响应

        Buffer = "" '清缓冲区字符

        'mciExecute "sound " & SystemPath & "\ringin.wav"

        Label1 = "状态：收到震铃"

        Zhen = True

        frmCallID.Show

        frmCallID.ChangRing

      ElseIf InStr(1, Buffer, "CONNECT", vbTextCompare) Then

      '对方应答呼叫

        Buffer = "" '清缓冲区字符

        Label1 = "状态：已经建立连接"

      ElseIf InStr(1, Buffer, "BUSY", vbTextCompare) Then

      '对方线路忙

        Buffer = "" '清缓冲区字符

        Label1 = "状态：对方线路忙"

      ElseIf InStr(1, Buffer, "No DIA", vbTextCompare) Then

        Buffer = "" '清缓冲区字符

        Label1 = "状态：拨出号码错,请检查电话线"

        Command1_Click

      ElseIf InStr(1, Buffer, "No CARRIER", vbTextCompare) Then

      '对方未摘机或未响应

        Buffer = "" '清缓冲区字符

        Label1 = "状态：对方未摘机"

      ElseIf InStr(1, Buffer, "NMBR =", vbTextCompare) Then

       tmpStr = InStr(1, Buffer, "NMBR", vbTextCompare)

       CallNum = Right(Buffer, Len(Buffer) - lll - 6)

       Label2.Caption = "对方电话：" + CallNum

        'Buffer = "" '清缓冲区字符

      ElseIf InStr(1, Buffer, "OK", vbTextCompare) And Asc(Right(Buffer, 1)) = 10 Then

       If Zhen = False Then Buffer = "" '清缓冲区字符

       If Command1.Caption = "挂断" Then

       Label2.Caption = "状态：已经播通电话：" + txtCallNum

      End If

      End If

End Sub