clslog.cls

一个VB实现串口通讯的经典示例.非常简明, 使用, 本人大部分通讯程序与之类同

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "clsLog"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Option Explicit

Private m_sPath As String, m_bOpened As Boolean
Private m_iFh As Integer

Public Property Get Path() As String
    Path = m_sPath
End Property

Public Property Get IsOpened() As Boolean
    IsOpened = m_bOpened
End Property

Public Sub CloseLog()
    If m_bOpened Then
        Close #m_iFh
        m_bOpened = False
    End If
End Sub

Public Function OpenLog(ByVal sPath As String) As Boolean
    sPath = Trim(sPath)
    CloseLog
    
    m_iFh = FreeFile
    On Error GoTo OpenLog_Error
    
    Open sPath For Append As #m_iFh
    m_bOpened = True
    
OpenLog_Error:
    If Err <> 0 Then
        MsgBox "Cannot open log file '" & sPath & "' for writing" & vbCrLf & "Error: " & Err.Description, vbOKOnly, "Open Log Error"
    End If
    
    On Error GoTo 0
    OpenLog = m_bOpened
End Function

Public Sub WriteLine(ByVal sMsg As String, Optional ByVal bLfAfterMsg As Boolean = True)
    If Not m_bOpened Then Exit Sub
    
    If bLfAfterMsg Then
        Print #m_iFh, sMsg
    Else
        Print #m_iFh, sMsg;
    End If
End Sub