用MSComm控件實現來電顯示

來電顯示的實現
MODEM的AT命令CID和VCID是設置是不是來電顯示的，如果電信開通了來電顯示功能
就能通過MODEM來顯示對方的電話號碼。那么首先設置CID=1或是VCID=1

般來說來電顯示的信息為：
DATE = MMDD "來電日期 MMDD
TIME = HHMM "來電時間 HHMM
NMBR = ######## "來電號碼
程序實現如下,設置MSComm1的相關設置，并建兩個Label為Label1和Label2
Function OpenCID(OpenCLose As Boolean) As Boolean
'打開或是關畢來電顯示功能
    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
下面的函數顯示來電號碼并在窗體上的Label1的Label2上顯示出來
Private Sub MSComm1_OnComm()
    On Error Resume Next
    Static Buffer As String
     ' 收到多于 RThreshold 屬性設置的字符數（RThreshold 屬性必須大于 0）。
            'label1 = "收到" + Str(MSComm1.InBufferCount) + "個字符"
            Buffer = Buffer + MSComm1.Input
            Buffer = UCase(Buffer)

         '   Exit Sub
            If InStr(1, Buffer, "RING", vbTextCompare) Then
            '收到震鈴
                'Comm1.Output = "ATA" + Chr(13) '命令 Modem 摘機響應
                Buffer = "" '清緩沖區字符
                'mciExecute "sound " & SystemPath & "\ringin.wav"
                Label1 = "狀態：收到震鈴"
                Zhen = True
                frmCallID.Show
                frmCallID.ChangRing
             
               
            ElseIf InStr(1, Buffer, "CONNECT", vbTextCompare) Then
            '對方應答呼叫
                Buffer = "" '清緩沖區字符
                Label1 = "狀態：已經建立連接"
            ElseIf InStr(1, Buffer, "BUSY", vbTextCompare) Then
            '對方線路忙
                Buffer = "" '清緩沖區字符
                Label1 = "狀態：對方線路忙"
            ElseIf InStr(1, Buffer, "No DIA", vbTextCompare) Then
                Buffer = "" '清緩沖區字符
                Label1 = "狀態：撥出號碼錯,請檢查電話線"
                Command1_Click
            ElseIf InStr(1, Buffer, "No CARRIER", vbTextCompare) Then
            '對方未摘機或未響應
                Buffer = "" '清緩沖區字符
                Label1 = "狀態：對方未摘機"
          
            ElseIf InStr(1, Buffer, "NMBR =", vbTextCompare) Then
             tmpStr = InStr(1, Buffer, "NMBR", vbTextCompare)
             CallNum = Right(Buffer, Len(Buffer) - lll - 6)
             Label2.Caption = "對方電話：" + CallNum

                'Buffer = "" '清緩沖區字符
            ElseIf InStr(1, Buffer, "OK", vbTextCompare) And Asc(Right(Buffer, 1)) = 10 Then
              If Zhen = False Then Buffer = "" '清緩沖區字符
             If Command1.Caption = "掛斷" Then
              Label2.Caption = "狀態：已經播通電話：" + txtCallNum
            End If
            End If
End Sub