adding item from text box to list box

[bpacheco1227]

I always have a problem with this. I get an error when trying to build the program "argument exception unhandled". Any help would be appreciated, thanks.

Private Sub addBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles addBtn.Click
        Dim newLineIndex As Integer = 0

        If My.Computer.FileSystem.FileExists(path & "stocks.txt") Then
            Do Until newLineIndex = -1
                lstdisplay.Items.Add(txtinput.Text)

            Loop
        End If
    End Sub

[markd220]

Not really sure what you're trying to do, but to add a string from the textbox to the list it's as simple as: lstdisplay.Items.Add(txtinput.Text) Are you trying to add the contents of the text file into a listbox? Also what are you trying to do with the loop?

[bpacheco1227]

yes, I'm trying to append contents of the textbox to the end of the listbox. The loop isn't correct I removed it already, I just need to get the contents of the textbox to append to the end of the listbox. Here is the complete code

Public Class Form1
    Private path As String = "E:\Visual Basic\"
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        lstdisplay.Items.Clear()
        My.Computer.FileSystem.OpenTextFileReader(path & "stocks.txt")
        lstdisplay.DataSource = IO.File.ReadAllLines(path & "stocks.txt")
    End Sub

    Private Sub exitBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles exitBtn.Click
        Me.Close()
    End Sub
    'Private Sub txtinput_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtinput.Enter
    '   txtinput.SelectAll()
    'End Sub
    Private Sub addBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles addBtn.Click
        'Dim newLineIndex As Integer = 0

        'If My.Computer.FileSystem.FileExists(path & "stocks.txt") Then
        'Do Until newLineIndex = -1
        lstdisplay.Items.Add(txtinput.Text)
        txtinput.Focus()
        '   Loop
        'End If
    End Sub



End Class

[bpacheco1227]

any thoughts on this one?

[waynespangler]

Will this help?

Dim zz As String = My.Computer.FileSystem.ReadAllText(path & "stocks.txt")
        Dim a As String() = Split(zz, vbNewLine)
        ListBox1.Items.AddRange(a)

[bpacheco1227]

no still didn't work, I'm stumped I've tried everything. Cannot add items to lstdisplay (listbox). Maybe because the listbox is being populated by a file?

[markd220]

The reason the code doesn't work is because adding an item to a listbox using the .items.add is different than setting the datasource. They don't work together.

If you want to continue to use the datasource (which I personally don't recommend) you can try this out. Use a variable for the datasource and append the txtInput to it and reset the datasource of the list.

Private path As String = "D:\Mark\"
    Dim datasource As New List(Of String)


    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        lstFile.Items.Clear()
        My.Computer.FileSystem.OpenTextFileReader(path & "ITS_Stuff.txt")

        Dim a() As String = IO.File.ReadAllLines(path & "ITS_Stuff.txt")
        For Each content As String In a
            datasource.Add(content)
        Next
        lstFile.DataSource = datasource
    End Sub


    Private Sub exitBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub
    'Private Sub txtinput_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtinput.Enter
    '   txtinput.SelectAll()
    'End Sub
    Private Sub addBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        'Dim newLineIndex As Integer = 0

        'If My.Computer.FileSystem.FileExists(path & "stocks.txt") Then
        'Do Until newLineIndex = -1
        datasource.Add(txtInput.Text())
        lstFile.DataSource = Nothing
        lstFile.DataSource = datasource
        lstFile.Refresh()

        txtinput.Focus()
        '   Loop
        'End If
    End Sub

A simpler way to do it is just to use the .items.add for the contents of the file and the txtInput

Private path As String = "D:\Mark\"

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        lstFile.Items.Clear()
        My.Computer.FileSystem.OpenTextFileReader(path & "ITS_Stuff.txt")

        Dim a() As String = IO.File.ReadAllLines(path & "ITS_Stuff.txt")
        For Each content As String In a
            lstFile.Items.Add(content)
        Next

    End Sub


    Private Sub exitBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub
    'Private Sub txtinput_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtinput.Enter
    '   txtinput.SelectAll()
    'End Sub
    Private Sub addBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        'Dim newLineIndex As Integer = 0

        'If My.Computer.FileSystem.FileExists(path & "stocks.txt") Then
        'Do Until newLineIndex = -1
        lstFile.Items.Add(txtInput.Text)

        txtinput.Focus()
        '   Loop
        'End If
    End Sub

[bpacheco1227]

thanks, now I can add items in the listbox. I also need to remove items when selected this is the code I have now but, of course it's not working, this is the code that I have so far

Private Sub removeBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles removeBtn.Click
        If lstdisplay.SelectedIndex > -1 Then
            lstdisplay.Items.RemoveAt(lstdisplay.SelectedIndex)

        End If
    End Sub

would I have to change the lstdisplay.Items.RemoveAt(lstdisplay.SelectedIndex) line to something like lstdisplay.datasource.????

[markd220]

If you are going to use the datasource approach, you'll have to modify the datasource variable and reset the datasource of the list.

Private path As String = "c:\"
    Dim datasource As New List(Of String)

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        lstFile.Items.Clear()
        Dim a() As String = IO.File.ReadAllLines(path & "dschat.log")

'I prefer to work with collections rather than arrays in .net so I'll move the array to a strongly typed List(Of ) collection
        For Each content As String In a
            datasource.Add(content)
        Next
        lstFile.DataSource = datasource
    End Sub

    ''' <summary>
    ''' Use this to refresh the list datasource.
    ''' </summary>
    ''' <remarks></remarks>
    Private Sub SetDatasource()
        lstFile.DataSource = Nothing
        lstFile.DataSource = datasource
        lstFile.Refresh()
    End Sub

    Private Sub removeBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles removeBtn.Click

        If lstFile.SelectedIndex > -1 Then
            datasource.RemoveAt(lstFile.SelectedIndex)
            SetDatasource()
        End If

    End Sub

    Private Sub addBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        datasource.Add(txtInput.Text())
        SetDatasource()
        txtInput.Focus()
    End Sub

[bpacheco1227]

Yes, thank you everything seems to be working beautifully. I added this to the exit button to write added content back to file.

Private Sub exitBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles exitBtn.Click
        If My.Computer.FileSystem.FileExists(path & "stocks.txt") Then
            My.Computer.FileSystem.WriteAllText(path & "stocks.txt", String.Empty, False)
        End If
        'loop to enter all data in list box into the file
        For Each item As String In lstdisplay.Items
            My.Computer.FileSystem.WriteAllText(path & "stocks.txt", item & ControlChars.NewLine, True)
        Next
        Me.Close()
    End Sub

and it actually works !!!

Thanks again!