代码没问题啊。要不试试下面弹出什么
'变量声明
Dim CardPUCIIN As Byte() = New Byte(254) {}
Dim pucManaMsg As Byte() = New Byte(254) {}
Dim pucCHMsg As Byte() = New Byte(254) {}
Dim pucPHMsg As Byte() = New Byte(3023) {}
Dim puiCHMsgLen As UInt32 = 0
Dim puiPHMsgLen As UInt32 = 0
Dim st As Integer = 0
'读卡操作
st = SDT_StartFindIDCard(1, CardPUCIIN, 1)
msgbox(st)
If st <> &H9f Then
Return
End If
st = SDT_SelectIDCard(1, pucManaMsg, 1)
msgbox(st)
If st <> &H90 Then
Return
End If
st = SDT_ReadBaseMsg(1, pucCHMsg, puiCHMsgLen, pucPHMsg, puiPHMsgLen, 1)
msgbox(st)
If st <> &H90 Then
Return
End If
'显示结果
msgbox(System.Text.ASCIIEncoding.Unicode.GetString(pucCHMsg))