VB 两个MScomm控件的问题。

MScomm1完全没有任何问题。收发自如。

MScomm2和MScomm1的编程模式一模一样。。但是都收不到数据啊。。

串口的灯在闪烁。说明确实收发成功了？

为什么不能在Text中显示呢?

还有别的需要注意的吗？ --------------------编程问答-------------------- 没有代码，无法回答。 --------------------编程问答-------------------- Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Private Sub Command1_Click()
MSComm2.PortOpen = True
End Sub

Private Sub Command3_Click()
Dim Temp(0) As Byte
Dim strBuff As String

If Option1.Value = True Then '如果显示16进制发送则进行16进制处理，这里只发送一个
   Temp(0) = "&H" & TextSend
   MSComm2.Output = Temp  '发送一个16进制
Else
     strBuff = TextSend
End If

If MSComm2.PortOpen = False Then
   MsgBox "请打开串口"
End If

On Error GoTo uerror
MSComm2.Output = strBuff
Label11.Caption = Label11.Caption + Len(strBuff)  '发送计数
uerror:
End Sub

Private Sub Form_Load()

If MSComm1.PortOpen = True Then MSComm1.PortOpen = False

If MSComm2.PortOpen = True Then MSComm2.PortOpen = False

Combo1.AddItem "COM1"
Combo1.AddItem "COM2"
Combo1.AddItem "COM3"
Combo1.AddItem "COM4"
Combo1.AddItem "COM5"
Combo1.AddItem "COM6"
Combo1.AddItem "COM7"
Combo1.AddItem "COM8"
Combo1.AddItem "COM9"
Combo1.AddItem "COM10"
Combo1.AddItem "COM11"
Combo1.AddItem "COM12"
Combo1.AddItem "COM13"
Combo1.AddItem "COM14"
Combo1.AddItem "COM15"
Combo1.AddItem "COM16"
Combo1.ListIndex = 2

Combo2.AddItem "256000"
Combo2.AddItem "128000"
Combo2.AddItem "115200"
Combo2.AddItem "57600"
Combo2.AddItem "38400"
Combo2.AddItem "28800"
Combo2.AddItem "19200"
Combo2.AddItem "14400"
Combo2.AddItem "12800"
Combo2.AddItem "11520"
Combo2.AddItem "9600"
Combo2.AddItem "4800"
Combo2.AddItem "2400"
Combo2.AddItem "1200"
Combo2.AddItem "600"

Combo3.AddItem "无校验"
Combo3.AddItem "奇校验"
Combo3.AddItem "偶校验"

Combo4.AddItem "4"
Combo4.AddItem "5"
Combo4.AddItem "6"
Combo4.AddItem "7"
Combo4.AddItem "8"

Combo5.AddItem "1"
Combo5.AddItem "2"

MSComm1.CommPort = Combo1.ListIndex + 1
MSComm1.Settings = "9600,n,8,1"
ComOpen.Caption = "打开串口"
Shape1.FillColor = &HFFFFC0

MSComm2.CommPort = 9
MSComm2.Settings = "9600,n,8,1"
MSComm2.InputMode = comInputModeBinary
End Sub
Private Sub ComOpen_Click()
On Error GoTo uerror      '发现错误跳转到错误处理

If ComOpen.Caption = "关闭串口" Then
        MSComm1.PortOpen = False
        ComOpen.Caption = "打开串口"  '按钮文字改变
        Shape1.FillColor = &HFFFFC0    '灯颜色改变
Else

       MSComm1.PortOpen = True
       ComOpen.Caption = "关闭串口"
       Shape1.FillColor = &HFF
End If
Exit Sub

uerror:
    msg$ = "无效端口号"          '错误显示
    Title$ = "串口调试助手"
    X = MsgBox(msg$, 48, Title$)  '48标示显示警告图标
End Sub

Private Sub MSComm1_OnComm()
    Dim BytReceived() As Byte
    Dim strBuff As String
    Dim i As Integer
    Select Case MSComm1.CommEvent    '事件发生
        Case 2
            Cls
            MSComm1.InputLen = 0     '读入缓冲区全部内容
            strBuff = MSComm1.Input  '读入到缓冲区
            Label10.Caption = Label10.Caption + Len(strBuff) '接收计数
         If MSComm1.InputMode = comInputModeBinary Then
            BytReceived() = strBuff  '如果是二进制接收模式则进行数据处理，否则直接显示字符串
            For i = 0 To UBound(BytReceived)
                If Len(Hex(BytReceived(i))) = 1 Then
                    strData = strData & "0" & Hex(BytReceived(i)) & " " '如果只有一个字符，则前补0，如F显示0F，最后补空格
                Else                                                    '方便显示观察如： 00 0F FE
                    strData = strData & Hex(BytReceived(i)) & " "
                End If
            Next
            TextReceive = TextReceive & strData
            strData = ""
        Else
            TextReceive = TextReceive & strBuff
        End If
    End Select
End Sub
Private Sub ComSend1_Click()   '手动发送

Dim Temp(0) As Byte
Dim strBuff As String

If Option1.Value = True Then '如果显示16进制发送则进行16进制处理，这里只发送一个
   Temp(0) = "&H" & TextSend
   MSComm1.Output = Temp  '发送一个16进制
Else
     strBuff = TextSend
End If

If MSComm1.PortOpen = False Then
   MsgBox "请打开串口"
End If

On Error GoTo uerror
MSComm1.Output = strBuff
Label11.Caption = Label11.Caption + Len(strBuff)  '发送计数
uerror:

End Sub
Private Sub ComSend2_Click()

If ComSend2.Caption = "自动发送" Then
    ComSend2.Caption = "关闭自动发送"
    Timer1.Interval = TextTime.Text
    Timer1.Enabled = True
Else
    ComSend2.Caption = "自动发送"
    Timer1.Enabled = False
End If

End Sub
Private Sub ComClean1_Click()

TextSend.Text = ""                      '清空发送窗口

End Sub

Private Sub MSComm2_OnComm()
Dim BytReceived() As Byte
    Dim strBuff As String
    Dim i As Integer
    Select Case MSComm2.CommEvent    '事件发生
        Case 2
            Cls
            MSComm2.InputLen = 0     '读入缓冲区全部内容
            strBuff = MSComm2.Input  '读入到缓冲区
            Label10.Caption = Label10.Caption + Len(strBuff) '接收计数
         If MSComm2.InputMode = comInputModeBinary Then
            BytReceived() = strBuff  '如果是二进制接收模式则进行数据处理，否则直接显示字符串
            For i = 0 To UBound(BytReceived)
                If Len(Hex(BytReceived(i))) = 1 Then
                    strData = strData & "0" & Hex(BytReceived(i)) & " " '如果只有一个字符，则前补0，如F显示0F，最后补空格
                Else                                                    '方便显示观察如： 00 0F FE
                    strData = strData & Hex(BytReceived(i)) & " "
                End If
            Next
            TextReceive = TextReceive & strData
            strData = ""
        Else
            TextReceive = TextReceive & strBuff
        End If
    End Select
End Sub

Private Sub Option3_Click()

MSComm1.InputMode = comInputModeBinary  '选择接收方式

End Sub
Private Sub Option4_Click()

MSComm1.InputMode = comInputModeText   '选择接收方式

End Sub

Private Sub Timer1_Timer()

Call ComSend1_Click      '定时调用手动发送

End Sub

Private Sub Timer2_Timer()

If Combo3 = "无校验" Then
   MSComm1.Settings = Str(Combo2) + "N" + Str(Combo4) + Str(Combo5)
ElseIf Combo3 = "奇校验" Then
   MSComm1.Settings = Str(Combo2) + "O" + Str(Combo4) + Str(Combo5)
ElseIf Combo3 = "偶校验" Then
   MSComm1.Settings = Str(Combo2) + "E" + Str(Combo4) + Str(Combo5)
End If

End Sub

Private Sub Combo1_Click()

If MSComm1.PortOpen = True Then  '如果串口打开先关闭后再进行其他操作
   MSComm1.PortOpen = False
End If
MSComm1.CommPort = Combo1.ListIndex + 1 '读取com口号

End Sub

Private Sub ComClean3_Click()

Label10.Caption = 0
Label11.Caption = 0

End Sub

Private Sub ComClean2_Click()

TextReceive.Text = ""   '接收窗口

End Sub
--------------------编程问答--------------------

引用 1 楼的回复:

没有代码，无法回答。

见代码。 --------------------编程问答-------------------- MSComm1和MSComm2分别对应不同的串口？ --------------------编程问答-------------------- 对啊对啊。～～

引用 4 楼的回复:

MSComm1和MSComm2分别对应不同的串口？

--------------------编程问答-------------------- MSComm2_OnComm中的strBuff应该定义为Variant数据类型:

Private Sub MSComm2_OnComm()

    Dim BytReceived() As Byte

    Dim strBuff As Variant

    Dim i As Integer

    Select Case MSComm2.CommEvent '事件发生

        Case 2

            Cls

            MSComm2.InputLen = 0 '读入缓冲区全部内容

            strBuff = MSComm2.Input '读入到缓冲区

            Label10.Caption = Label10.Caption + Len(strBuff) '接收计数

            If MSComm2.InputMode = comInputModeBinary Then

                BytReceived() = strBuff '如果是二进制接收模式则进行数据处理，否则直接显示字符串

                For i = 0 To UBound(BytReceived)

                If Len(Hex(BytReceived(i))) = 1 Then

                    strData = strData & "0" & Hex(BytReceived(i)) & " " '如果只有一个字符，则前补0，如F显示0F，最后补空格

                Else '方便显示观察如： 00 0F FE

                    strData = strData & Hex(BytReceived(i)) & " "

                End If

                Next

                TextReceive = TextReceive & strData

                strData = ""

            Else

                TextReceive = TextReceive & strBuff

            End If

    End Select

End Sub

--------------------编程问答-------------------- MScomm1中的不用Variant类型啊。。是可以的鹅

引用 6 楼的回复:

MSComm2_OnComm中的strBuff应该定义为Variant数据类型:

VB code
Private Sub MSComm2_OnComm()
    Dim BytReceived() As Byte
    Dim strBuff As Variant
    Dim i As Integer
    Select Case MSComm2.CommEvent '事件发生……

--------------------编程问答-------------------- 将下位机对换一下串口，检查是否是下位机或者有问题

补充：VB ,  控件