VB6 到 VB.NET 的转换（语法：打印到 StreamWriter/Reader）？

Question

以下代码是 VB6 应用程序的一部分，我目前正在转换为 VB.NET Windows 服务。以 Open 开头的行给我一个错误（我假设 'Open' 语法不支持 VB.NET）。我尝试利用我拥有的所有 VB.NET 知识转换代码，但想知道 ideal/optimistic 解决方案。

VB6 代码

Private Sub Text1_GotFocus()
Me.lblCompanyName.Caption = ""
Me.lblCompanyName.Refresh

lngPosted = 0
lngSkipped = 0
lngClosed = 0

strMsg = Dir(strPath & "\WisysDataCollector_*.log", vbNormal)
        Do While strMsg <> ""
            On Error Resume Next
            If strMsg < "WisysDataCollector_" & Format(DateAdd("m", -12, Now), "yyyyMM") Then
                Kill(strPath & "\" & strMsg)
            End If
            On Error GoTo 0
            strMsg = Dir()
        Loop

        datTimeStart = Now
        Do
            On Error Resume Next
            Open strPath & "\WisysDataCollector_" & Format(Now, "yyyyMM") & ".log" For Append Lock Read Write As #1 
            lngST = Err.Number
            strMsg = Err.Description
            On Error GoTo 0
            If lngST = 0 Then
                Exit Do
            End If

           dblTimeElapsed = (Now - datTimeStart) * 24 * 60 * 60

           If dblTimeElapsed > 20 Then
        
               varResponse = vbCancel
               If varResponse = vbCancel Then
                   strStatus = "Log file busy.  Process aborted."
                   GoTo EXITFORM
               End If
               datTimeStart = Now
           End If
        Loop

Code continues.......

我试过的：创建了一个 'FileIO' class 如下 IO.StreamWriter 和 IO.StreamReader

Public Class FileIO
    Public Shared Sub WriteLog(strToWrite As String)
        Dim filePath As String = AppDomain.CurrentDomain.BaseDirectory + "\WisysDataCollector_" + Format(Now, "MMddyy") + ".log"
        Dim streamWr As IO.StreamWriter = Nothing
        Try
            streamWr = New IO.StreamWriter(filePath, True)

            streamWr.Write(Now + " - " + strToWrite + vbNewLine)
            streamWr.Flush()
            streamWr.Close()
        Catch ex As Exception

        End Try
    End Sub

    Public Shared Sub ReadLog(strToWrite As String)
        Dim filePath As String = AppDomain.CurrentDomain.BaseDirectory + "\WisysDataCollector_" + Format(Now, "MMddyy") + ".log"
        Dim streamRd As IO.StreamReader = Nothing
        Try
            streamRd = New IO.StreamReader(filePath, True)

            streamRd.Read()
            streamRd.Close()
        Catch ex As Exception

        End Try
    End Sub
End Class

请告诉我我在上面的代码中犯的错误以及我应该如何使用 'FileIO' class 来更正 'Open' 和 [=38= 的错误]?

此外，如果有人可以通过此代码行澄清他们试图做什么（老实说，我试图理解但不确定他们为什么将时差乘以 24 * 60 * 60）dblTimeElapsed = (Now - datTimeStart) * 24 * 60 * 60?

Answer 1

& 符号 & 是 vb.net 的连接字符。虽然加号通常会起作用，但如果涉及数字，您可能会得到意想不到的结果。

必须释放流以释放非托管资源。 Using...End Using 积木帮我们解决了这个问题。

我将filePath设置为class级变量，因为它在不止一种方法中使用。这也必须是 Shared 因为它用在 Shared 方法中。我更改了日期格式，因此它会按时间顺序显示在文件资源管理器中。

阅读日志而不对其进行任何操作是没有意义的。我将 ReadLog 方法更改为 Function。给它传递一个字符串也是没有意义的。

我相信 vb6 代码试图用 24 60 60 业务以秒为单位表示经过的时间。我给你举了一个例子 Form.Load 设置 startTime 然后在一段时间后按下按钮并计算已经过去的秒数。

形式为class...

Private StartTime As DateTime

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    StartTime = Now
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    FileIO.WriteLog(TextBox1.Text)
End Sub

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    TextBox2.Text = FileIO.ReadLog
End Sub

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
    Dim elapsedTime As TimeSpan = Now - StartTime
    Dim TotalSeconds = elapsedTime.TotalSeconds
    MessageBox.Show($"The elapsed time since the program started is {TotalSeconds}")
End Sub

您的 class 看起来像这样...

Public Class FileIO
    Private Shared filePath As String = AppDomain.CurrentDomain.BaseDirectory & "\WisysDataCollector_" & Format(Now, "yyyyMMdd") & ".log"

    Public Shared Sub WriteLog(strToWrite As String)
        Using sw = File.AppendText(filePath)
            sw.WriteLine(strToWrite)
        End Using
    End Sub

    Public Shared Function ReadLog() As String
        If File.Exists(filePath) Then
            Return File.ReadAllText(filePath)
        Else
            Return ""
        End If
    End Function
End Class

VB6 到 VB.NET 的转换（语法：打印到 StreamWriter/Reader）？

VB6 to VB.NET conversion (Syntax : Print to StreamWriter/Reader)?

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