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

The following code is a part of VB6 application & I'm currently converting to VB.NET Windows Service. Line starts with Open gives me an error(I assume the 'Open' syntax does not support with VB.NET). I tried converting the code utilizing all the VB.NET knowledge I have but would like to know the ideal/optimistic solution.

VB6 Code

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.......

What I've tried : Created a 'FileIO' class as following with IO.StreamWriter and 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

Please let me know the errors I've made in the above code also how should I use the 'FileIO' class to correct the errors with 'Open' and 'Print #1'?

Also if someone can please clarify what were they trying to do by this code line(honestly I'm trying to understand but not sure why they've multiplied the time difference by 24 * 60 * 60) dblTimeElapsed = (Now - datTimeStart) * 24 * 60 * 60?

The ampersand, &, is the concatenation character for vb.net. Although the plus sign will usually work, if numbers are involved you could get unexpected results.

Streams must be disposed to released unmanaged resources. Using...End Using blocks take care of this for us.

I made filePath a class level variable because it is used in more than one method. This must also be Shared because it is used in Shared methods. I changed the format of date so it will appear chronologically in File Explorer.

It makes no sense to read the log and do nothing with it. I changed the ReadLog method to a Function. It also makes no sense to pass a string to it.

I believe the vb6 code was trying to express elapsed time in seconds with the 24 60 60 business. I gave you an example of that with the Form.Load setting the startTime and then hitting a button some time later and calculating the seconds that had passed.

In the form 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

Your class would look like this...

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