突破MsComm控件RThreshold限制，全部数据统统收！

全局参数：

Private Rv_data() As Byte '存放接收的数据

Private tmpRV() As Byte '存放暂存的数据

Private Declare Sub Sleep Lib 'kernel32' (ByVal dwMilliseconds As Long)

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Form_Load ()中先初始化控件参数

With MSComm1

.Settings = '9600,N,8,1'

.InputMode = 1 '设置接受数据的类型是二进制类型数据

.InputLen = 8 '一次性从接收缓冲区中读取所有数据(8个字节为一组)

.InBufferCount = 0 '清空接收缓冲区

.OutBufferCount = 0 '清空发送缓冲区

.SThreshold = 0 '一旦发送数据就触发OnComm()事件来检测是否返回数据

.RThreshold = 1 '接收到1个字节数据就立即触发OnComm()事件

.CommPort = 1 '使用第一个串口

.PortOpen = True '打开串口

End With

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思路是这样的：按8个为一组然后一组一组地进行取出，直到缓冲区数据全部取完为止

Private Sub MSComm1_OnComm()

Dim UB1%, UB2%, TM As Integer, i As Integer

Select Case MSComm1.CommEvent

Case comEvReceive

Sleep (20) '相隔20ms就可以正确接收到24个字节的数据

Do While MSComm1.InBufferCount > 0

TM = TM + 1

If TM = 1 Then

Rv_data = MSComm1.Input

Else

tmpRV = MSComm1.Input

UB1 = UBound(Rv_data)

UB2 = UBound(tmpRV) + 1 '元素比下标大1

ReDim Preserve Rv_data(UB1 + UB2)

For i = UB1 + 1 To UB1 + UB2

Rv_data(i) = tmpRV(i - UB1 - 1)

Next i

End If

Loop

If Check_RvData Then

Call Response_OK() '这里用来进行正确的处理

Else

Call Response_Bad() '这里用来进行错误处理

End If

Erase tmpRV

Erase Rv_data

End Select

End Sub

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