Question

VB编程mscomm控件问题?高手请进

用VB编程用MSCOMM控件获取串口数据,比如我要在接收数据时,遇到#字符开始接收数据,遇到!字符就停止接收,就显示TEXT中,请问怎么mscomm控件的OnComm事件中怎么写代码?

MSComm1.CommPort = 1
MSComm1.Settings = "19200,n,8,1"
MSComm1.PortOpen = True
MSComm1.InputMode = comInputModeText
请问一下 mscomm控件的MSComm1.RThreshold属性设置为1?

Answer 1

Option Explicit
Dim strData As String
Private Sub Form_Load()
MSComm1.CommPort = 1 'COM端口
MSComm1.Settings = "9600,n,8,1"
MSComm1.InputMode = comInputModeText
MSComm1.InBufferCount = 0 '清空接受缓冲区
MSComm1.OutBufferCount = 0 '清空传输缓冲区
MSComm1.RThreshold = 1 '产生MSComm事件
MSComm1.InBufferSize = 1024
MSComm1.PortOpen = True
Text1 = ""

End Sub

Private Sub MSComm1_OnComm() '接收数据
Dim BytReceived() As Byte
Dim strBuff As String
Select Case MSComm1.CommEvent
Case 2
MSComm1.InputLen = 0
strData = strData & MSComm1.Input
'数据处理代码
If Left(strData, 1) = "#" And Right(strData, 1) = "!" Then
Text1 = strData
Else
strData = ""
End If
End Select
End Sub

Answer 2

首先要知道你串口设备返回的是asc码,还是16进制数
MSComm1.InputMode = comInputModeText '返回的asc码

do while mscomm1.InBufferCount>1
if instr(mscomm1.input,"#")<>0 then
me.text1.text=me.text1.text & mscomm1.input
doevents
end if
if instr(mscomm1.input,"!")<>0 then exit do
loop