求教:有关mscomm控件的多次发送问题!
请教:
我写了一个读卡程序,每次发送一组数据给读卡器,读卡器可正常接收.但当我一次要传送四组数据时(也就是连续向读写卡器发送4次写入4个不同地址的4个数据),我发现读写卡器有时接收不到任何数据(MSComm1_OnComm()事件没执行),但偶尔又只能写入其中两个地址.如果去掉任意三个写入的数据(只写入一个),程序又能写入了.为什么???请大家帮帮忙!
程序的思路大致如下:
Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.InputMode = comInputModeBinary
MSComm1.RThreshold = 1
MSComm1.InputLen = 0
MSComm1.Settings = "9600,n,8,1"
MSComm1.InBufferSize = 1024
MSComm1.OutBufferSize = 1024
End Sub
Private Sub Command1_Click()
bh = Left(Trim(Text2.Text), 1)
lb = "2"
sj = Trim(Text2.Text)
stat = xieka(bh, lb, sj)
If Trim(Text1.Text) <> Trim(Text2.Text) And Trim(Text1.Text) <> "" Then
lb = "1"
sj = Trim(Text1.Text)
stat = xieka(bh, lb, sj)
End If
If Trim(Text3.Text) <> "" Then
lb = "3"
sj = Trim(Text3.Text)
stat = xieka(bh, lb, sj)
End If
If Trim(Text4.Text) <> "" Then
lb = "4"
sj = Trim(Text4.Text)
stat = xieka(bh, lb, sj)
End If
End Sub
Function xieka(Strbh As String, Strlb As String, Strsj As String) As String
写卡数据处理代码
End Function
Private Sub MSComm1_OnComm()
数据接收处理代码
End Sub
谁能告诉我问题所在吗?不胜感激!