VB串口通信(附图教程)

界面如下：

代码如下：

Private Sub Form_Load()

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

End If

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None"

Combo3.AddItem "奇Odd"

Combo3.AddItem "偶Even"

Combo4.AddItem "4"

Combo4.AddItem "5"

Combo4.AddItem "6"

Combo4.AddItem "7"

Combo4.AddItem "8"

Combo5.AddItem "1"

Combo5.AddItem "2"

https://www.360docs.net/doc/f712087694.html,mPort = Combo1.ListIndex + 1 MSComm1.Settings = "9600,n,8,1"

ComOpen.Caption = "打开串口"

Shape1.FillColor = &HFFFFC0

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 https://www.360docs.net/doc/f712087694.html,mEvent '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

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 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None" Then

MSComm1.Settings = Str(Combo2) + "N" + Str(Combo4) + Str(Combo5) ElseIf Combo3 = "奇Odd" Then

MSComm1.Settings = Str(Combo2) + "O" + Str(Combo4) + Str(Combo5) ElseIf Combo3 = "偶Even" 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

https://www.360docs.net/doc/f712087694.html,mPort = 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

功能上：实现了字符串的发送和接收，8位数据的十六进制发送和接收，有端口，波特率等设置。

缺点：

1：只可以发送两位十六进制数。

2：接收和发送的显示数据上有点不同步，十六进制的没有算进去。

3：没有TXT的文件发送和接收的功能。

如需要源程序的，可下载本文的图片，下载后把图片的.jpg格式改为.rar格式就可以解压出来了。

附：MSComm控件的属性：

属性

说明

(Name)

MSComm控件的名称

(自定义)

打开属性页

CommPort

获得或设置通讯端口号

DTREnable

决定在通讯过程中是否使数据终端机状态线有效。取值为：

True

False

EOFEnable

获得或设置是否搜索EOF字符。取值为：

True

False

Handshaking

获得或设置软件的握手协议。取值为：

0 comNone

1 comXOnXoff

2 comRTS

3 comRTSXOnXOff

InBufferSize

获得或设置接收缓冲区的大小，以字节数为单位。

Index

在对象数组中的编号

InputLen

获得或设置输入属性从接收缓冲区读出的字符数。

InputMode

获得或设置输入属性检索的数据类型。取值为：

0 comInputModeText

1 comInputModeBinary

Left

距离容器左边框的距离

NullDiscard

决定是否将空字符串从端口传送到接收缓冲区。取值为：

True

False

OutBufferSize

获得或设置传输缓冲区中的字符数

ParityReplace

获得或设置当出现奇偶校验错误时，用来替换数据流中无效字符的字符。RThreshold

获得或设置要接受的字符数。

RTSEnable

决定能否使行有效。取值为：

True

False

Settings

获得或设置波特率、奇偶校验、数据位和停止位参数。

SThreshold

获得或设置传输中所能允许的最小字符数

Tag

存储程序所需的附加数据

Top

距容器顶部边界的距离