''' <summary>    ''' 寫日志    ''' </summary>    ''' <param name="msg">日志內容</param>    ''' <param name="context">上下文對象</param>    ''' <remarks></remarks>    Sub WriteLog(msg As String, Optional context As System.Web.HttpContext = Nothing)        Dim filepath As String = ""        If context Is Nothing Then            filepath = Me.LogFilePath        Else            filepath = context.Server.MapPath("..") + "/File/LogFile/"        End If        filepath &= Now.ToString("yyyyMMdd") & ".txt"        Dim content As String        If context IsNot Nothing Then            content = "<-------------異常時間:" & Now.ToString("yyyy-MM-dd HH:mm:ss") & _                Chr(13) & msg & "來源:" & context.Request.Url.ToString & _                "錯誤信息:" & context.Error.Message & _                Chr(13) & "錯誤詳情:" & Chr(13) & context.Error.StackTrace & Chr(13) & _                "--------------->" & Chr(13)        Else            content = "異常時間:" & Now.ToString("yyyy-MM-dd HH:mm:ss") + Chr(13) & msg & Chr(13)        End If        File.AppendAllText(filepath, content)    End Sub