VB6接收和发送can报文代码

在VB6中，要接收和发送CAN报文需要使用一个CAN卡的驱动程序。以下是一个简单的示例代码，可以通过CAN卡接收和发送报文：

' 引入需要的库文件
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Private Declare Function StartCAN Lib "你的CAN卡驱动库文件.dll" () As Long
Private Declare Function StopCAN Lib "你的CAN卡驱动库文件.dll" () As Long
Private Declare Function SendCAN Lib "你的CAN卡驱动库文件.dll" (ByVal ID As Long, ByVal Data As String, ByVal Len As Long) As Long
Private Declare Function ReceiveCAN Lib "你的CAN卡驱动库文件.dll" (ByVal ID As Long, ByVal Data As String, ByRef Len As Long) As Long

' 打开CAN卡
Private Function OpenCAN() As Boolean
    Dim Ret As Long
    Ret = StartCAN()
    If Ret < 0 Then
        OpenCAN = False
    Else
        OpenCAN = True
    End If
End Function

' 关闭CAN卡
Private Function CloseCAN() As Boolean
    Dim Ret As Long
    Ret = StopCAN()
    If Ret < 0 Then
        CloseCAN = False
    Else
        CloseCAN = True
    End If
End Function

' 发送CAN报文
Private Function SendCANMsg(ByVal ID As Long, ByVal Data As String, ByVal Len As Long) As Boolean
    Dim Ret As Long
    Ret = SendCAN(ID, Data, Len)
    If Ret < 0 Then
        SendCANMsg = False
    Else
        SendCANMsg = True
    End If
End Function

' 接收CAN报文
Private Function ReceiveCANMsg(ByRef ID As Long, ByRef Data As String, ByRef Len As Long) As Boolean
    Dim Ret As Long
    Ret = ReceiveCAN(ID, Data, Len)
    If Ret < 0 Then
        ReceiveCANMsg = False
    Else
        ReceiveCANMsg = True
    End If
End Function

' 主程序
Private Sub Main()
    Dim ID As Long
    Dim Data As String
    Dim Len As Long
    
    ' 打开CAN卡
    If Not OpenCAN() Then
        MsgBox "Open CAN Card Failed!"
        Exit Sub
    End If
    
    ' 循环发送和接收CAN报文
    Do While True
        ' 发送CAN报文
        ID = 0x01
        Data = "11223344"
        Len = 4
        If Not SendCANMsg(ID, Data, Len) Then
            MsgBox "Send CAN Msg Failed!"
        End If
        
        ' 接收CAN报文
        ID = 0
        Data = String(8, 0)
        Len = 0
        If ReceiveCANMsg(ID, Data, Len) Then
            MsgBox "Received CAN Msg, ID=" & ID & ", Data=" & Data & ", Len=" & Len
        Else
            MsgBox "Receive CAN Msg Failed!"
        End If
        
        ' 等待一段时间
        Sleep 100
    Loop
    
    ' 关闭CAN卡
    CloseCAN
End Sub

注意：以上代码只是一个简单的示例，具体的使用还需要根据自己的CAN卡驱动程序进行调整。