Vb.net Load multiple lines from a textfile to different listboxes

Question

Intro

Alright so I have a load and a save button. I'm going to save all listbox items to a .txt file and then load them up to the listbox.

Now, this would be pretty simple if it was just one listbox. My problem is that its 9 listboxes, and just one .txt file that contains all the items from the 9 listboxes. I don't want 9 different .txt files. And keep in mind that how many items the listboxes contains varies.

This is how the save button outputs to the .txt file (Another version further down)

Channel 1
c:\folder\folder

Channel 2
\\server\folder\foldera
\\server\folder\folderb

Channel 3
\\anotherserver\foldera
\\anotherserver\folderb
\\anotherserver\folderc
\\anotherserver\folderd
\\anotherserver\foldere

Channel 4
\\somepath\folder\folder\foldera

Channel 5
\\server\folder\foldera

Channel 6
\\server\folder\foldera

\\server\folder\foldera

Channel 8
\\server\folder\foldera

Channel 9
\\server\folder\foldera

Each channel is the listboxes and the paths is the items that each listbox contains.

Here is my save btnsave.click

Dim configfile As String = "C:\Applicationpath\Config\" & System.DateTime.Now.ToString("yyyyMMdd") & "_Config.txt"

Using fs As FileStream = File.Create(configfile)
fs.Close()
End Using

Write_Configfile()

... and Write_config() does the following:

    Dim objWriter As New System.IO.StreamWriter(configfile, True)
    Try
        objWriter.WriteLine("Channel 1")
        For Each itm1 As String In Me.lbchannel1.Items
            objWriter.WriteLine(itm1)
        Next
        objWriter.WriteLine(" ")

        objWriter.WriteLine("Channel 2")
        For Each itm2 As String In Me.lbChannel2.Items
            objWriter.WriteLine(itm2)
        Next
        objWriter.WriteLine(" ")

and all the way to channel 9. There is probably a easier way to do this, I know.

The problem and question

Now to the load button. I thought that if I can load each listbox from a spesified part of the textfile I would be fine. I'd love to say "Hey, add all the items to channel 1 (listbox1) that are written between "Channel 1" and "Channel 2" in the configfile - and so on to channel 9. And this is where I'm stuck.

I need to readline after a certain word or between certain words. Not read a certain line, because like I said how many items the listboxes contains varies.

Keep in mind that I can change the save output to look like this if that makes things easier:

c1:c:\folder\folder   
c2:\\server\folder\foldera
c2:\\server\folder\folderb
'and so on... 

So my attempt to that have been this:

    If OpenFileDialog1.ShowDialog = DialogResult.OK Then

        Using reader As New StreamReader(OpenFileDialog1.FileName.ToString)
            Dim line As String = reader.ReadLine(OpenFileDialog1.FileName)
            If line = "c1:" Then
                lbchannel1.Items.Add(line) 'lbchannel1 is listbox1
            End If
            'if line = "c2:" then
            'blablabla
            'if line = "c3:" then
            'same goes to c9
        End Using
    End If

But this gives me this error {"Conversion from string C:\Applicationpath\Config\20160405_config.txt to type integer is not valid."} and I'm sure its not the correct way to do it.

Answer 1

If you adapt the names of your listboxes and the headings in your textfile so that they are equal, there is a generic solution for that.

Change Write_config() so that it write Channel1 instead of Channel 1 etc.:

Dim objWriter As New System.IO.StreamWriter(configfile, True)
For Each o As ListBox In Me.Controls.OfType(Of ListBox).Where(Function(c) c.Name.StartsWith("Channel"))
    objWriter.WriteLine(o.Name)
    For Each itm As String In o.Items
        objWriter.WriteLine(itm1)
    Next
Next

Also change the names of your listbox controls to Channel1 up to Channel9.

New TextFile would look like:

Channel1
c:\folder\folder

Channel2
\\server\folder\foldera
\\server\folder\folderb
...

Now change the code for filling the listboxes:

Using reader As New StreamReader(OpenFileDialog1.FileName.ToString)
        Dim currentListBox As ListBox = Nothing

        While reader.Peek > -1
            Dim line As String = reader.ReadLine()
            If Not String.IsNullOrEmpty(line) Then
                Dim tmpListBox = Controls.Find(line, false) 'Try to find listbox according to line 
                If tmpListBox.Any() Then 'It´s a listbox name
                   currentListBox = DirectCast(tmpListBox(0), ListBox)
                Else 'It´s a folder name
                   currentListBox.Items.Add(line) 
                End If
            End If
       End While
 End Using

Answer 2

Remove the filename from your ReadLine. Then add a Split and Select Case to determine which control to populate.

        Using reader As New StreamReader(OpenFileDialog1.FileName.ToString)
            Dim line As String = reader.ReadLine()
            Dim values() As String = line.Split(":")
            Select Case values(0)
                Case "C1"
                    lbchannel1.items.add(values(1))

                Case "C2"
                    lbchannel2.items.add(values(1))
            End Select

        End Using

Answer 3

For you Save function, you can go with something like this :

Using objWriter As New System.IO.StreamWriter(configfile, True)
    Try
        'We will run through each channel
        For i = 1 to 9
            objWriter.WriteLine("Channel " & i.ToString())
            'We find the ListBox based on its name
            Dim LB As ListBox = CType(Me.Controls.Find("lbchannel" & i.ToString(), True), ListBox)
            For Each itm As String In LB.Items
                objWriter.WriteLine(itm)
            Next
            objWriter.WriteLine("")
        Next
    Catch ex as Exception
        'Exception Handling here
    End Try
End Using

Then you will want to load the file the following way :

Using reader As New StreamReader(OpenFileDialog1.FileName)
    Dim Line As String = reader.ReadLine()
    Dim CurrentChanel as Integer = 0
    Dim LB As ListBox = Nothing
    While Not IsNothing(Line) 'It will be Nothing when file is over
        If Line.StartsWith("Channel ") Then
            'We will increment CurrentChannel, as we changed the section
            CurrentChannel += 1
            LB = CType(Me.Controls.Find("lbchannel" & CurrentChannel.ToString(), True), ListBox)
        Else If Line <> "" Then
            LB.Items.Add(Line)
        End If
        Line = reader.ReadLine()
    End While
End Using