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How to save listbox items to a file

    Question

  • Hi,

    I need to save items present in a list box to some file (need not be .txt). Also, the next time the user opens the form, the list box should display the items. How can I do this?

    Thanks,

    Rahul

    Monday, November 05, 2012 12:54 PM

Answers

  • If using VS2008 or higher here are some language extensions

    Usage

    ListBox1.Items.SaveToFile("Your File Name")

    Code

        ''' <summary>
        ''' Save unbound items to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String)
            System.IO.File.WriteAllLines(FileName,
                (From Row In sender.Cast(Of String)() Select Row).ToArray())
        End Sub
        ''' <summary>
        ''' Save unbound items to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <param name="Append">Indicates whether new contents should be appended to existing file</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String, ByVal Append As Boolean)
            Dim Items = (From Row In sender.Cast(Of String)() Select Row).ToList
            If Append Then
                If IO.File.Exists(FileName) Then
                    Dim CurrentFileLines = IO.File.ReadAllLines(FileName).ToList
                    Items.AddRange(CurrentFileLines)
                End If           
            End If
            System.IO.File.WriteAllLines(FileName, Items.ToArray)
        End Sub
        ''' <summary>
        ''' Save one column of a bound listbox to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <param name="ColumnName">Name of column to write to disk</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String, ByVal ColumnName As String)
            System.IO.File.WriteAllLines(FileName,
                (
                    From Row In sender.Cast(Of DataRowView)()
                    Select CStr(Row.Item(ColumnName))).ToArray())
        End Sub
        ''' <summary>
        ''' Save one column of a bound listbox to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <param name="ColumnIndex">Index of column to write to disk</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String, ByVal ColumnIndex As Integer)
            System.IO.File.WriteAllLines(FileName,
                (
                    From Row In sender.Cast(Of DataRowView)()
                    Select CStr(Row.Item(ColumnIndex))).ToArray())
        End Sub
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub LoadFromFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String)
            sender.AddRange(IO.File.ReadAllLines(FileName))
        End Sub


    KSG

    Monday, November 05, 2012 4:14 PM
    Moderator
  • Rahuly,

    You’ve seen the other variations on this and since you said you’re not restricting your thoughts only to .txt files, how about an XML file? While we’re at it, let’s let it save all ListBox data in one go and then reload that XML data when the user asks for it to.

    I put a little program together that will allow me to load some “dummy text” into four ListBoxes when I click a button:

    As you can see there, now the Reload List(s) button is enabled but instead of clicking it, I want you to see that it will load it back from scratch so I closed and re-opened the program:

    If you’re interested, you can see the results of the XML output here and I have the code on a page of my website here.

    I hope you find this and the other posts useful. :)


    Please call me Frank :)

    Monday, November 05, 2012 11:12 PM

All replies

  • I set this up to save listbox entries to a file when the form closes and add file entries to a listbox when the form opens. The file contains three lines (apples, oranges and pears).

    Imports System.IO
    
    Public Class Form1
    
        Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
            Dim Filepath As String = ("C:\Users\John\Desktop\Test.txt")
            Dim sr As StreamReader
            sr = New StreamReader(Filepath)
            Do Until sr.EndOfStream
                ListBox1.Items.Add(sr.ReadLine)
            Loop
            sr.Close()
    
        End Sub
    
        Private Sub ListBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListBox1.SelectedIndexChanged
    
        End Sub
    
        Private Sub Form1_Closing(sender As Object, e As EventArgs) Handles Me.FormClosing
            Dim Filepath As String = ("C:\Users\John\Desktop\Test.txt")
            Dim sw As StreamWriter
            sw = File.CreateText(Filepath)
            Dim ListOfItems As String
            Do Until ListBox1.Items.Count.Equals(0)
                ListOfItems = ListBox1.Items.Item(0)
                ListBox1.Items.RemoveAt(0)
                sw.WriteLine(ListOfItems)
            Loop
            sw.Flush()
            sw.Close()
        End Sub
    
    End Class


    You've taught me everything I know but not everything you know.

    Monday, November 05, 2012 3:34 PM
  • If using VS2008 or higher here are some language extensions

    Usage

    ListBox1.Items.SaveToFile("Your File Name")

    Code

        ''' <summary>
        ''' Save unbound items to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String)
            System.IO.File.WriteAllLines(FileName,
                (From Row In sender.Cast(Of String)() Select Row).ToArray())
        End Sub
        ''' <summary>
        ''' Save unbound items to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <param name="Append">Indicates whether new contents should be appended to existing file</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String, ByVal Append As Boolean)
            Dim Items = (From Row In sender.Cast(Of String)() Select Row).ToList
            If Append Then
                If IO.File.Exists(FileName) Then
                    Dim CurrentFileLines = IO.File.ReadAllLines(FileName).ToList
                    Items.AddRange(CurrentFileLines)
                End If           
            End If
            System.IO.File.WriteAllLines(FileName, Items.ToArray)
        End Sub
        ''' <summary>
        ''' Save one column of a bound listbox to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <param name="ColumnName">Name of column to write to disk</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String, ByVal ColumnName As String)
            System.IO.File.WriteAllLines(FileName,
                (
                    From Row In sender.Cast(Of DataRowView)()
                    Select CStr(Row.Item(ColumnName))).ToArray())
        End Sub
        ''' <summary>
        ''' Save one column of a bound listbox to a file
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="FileName">File to save items too</param>
        ''' <param name="ColumnIndex">Index of column to write to disk</param>
        ''' <remarks></remarks>
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub SaveToFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String, ByVal ColumnIndex As Integer)
            System.IO.File.WriteAllLines(FileName,
                (
                    From Row In sender.Cast(Of DataRowView)()
                    Select CStr(Row.Item(ColumnIndex))).ToArray())
        End Sub
        <System.Runtime.CompilerServices.Extension()> _
        Public Sub LoadFromFile(ByVal sender As ListBox.ObjectCollection, ByVal FileName As String)
            sender.AddRange(IO.File.ReadAllLines(FileName))
        End Sub


    KSG

    Monday, November 05, 2012 4:14 PM
    Moderator
  • You are perfectly right. The code I posted is garbage. I had a List(of .....) in mind and used ListBox instead. I have removed the offending post.

    Regards Les, Livingston, Scotland

    Monday, November 05, 2012 4:40 PM
  • You are perfectly right. The code I posted is garbage. I had a List(of .....) in mind and used ListBox instead. I have removed the offending post.

    Regards Les, Livingston, Scotland


    I removed my comment too

    KSG

    Monday, November 05, 2012 6:22 PM
    Moderator
  • Rahuly,

    You’ve seen the other variations on this and since you said you’re not restricting your thoughts only to .txt files, how about an XML file? While we’re at it, let’s let it save all ListBox data in one go and then reload that XML data when the user asks for it to.

    I put a little program together that will allow me to load some “dummy text” into four ListBoxes when I click a button:

    As you can see there, now the Reload List(s) button is enabled but instead of clicking it, I want you to see that it will load it back from scratch so I closed and re-opened the program:

    If you’re interested, you can see the results of the XML output here and I have the code on a page of my website here.

    I hope you find this and the other posts useful. :)


    Please call me Frank :)

    Monday, November 05, 2012 11:12 PM
  • Hi,

    I'm sorry but this didn't work - when I open the form for the first time I get a System.IO exception saying the file never existed (true).

    Thanks,

    Rahul

    Wednesday, November 07, 2012 11:01 AM
  • Hi Kevin,

    Should I use the one line of code which you gave or the other code sample? I have Visual Studio 2010 Ultimate.

    Wednesday, November 07, 2012 11:03 AM
  • You’ve seen the other variations on this and since you said you’re not restricting your thoughts only to .txt files, how about an XML file?

    I only said that because I don't really want people to simply change the contents of the text file (this particular form takes user reviews in a particular computer and puts them I have put filters for bad reviews but I wouldn't want people to write bad reviews in the txt file). I'll try out your code.

    Thanks,

    Rahul

    Wednesday, November 07, 2012 11:07 AM
  • Hi Kevin,

    Should I use the one line of code which you gave or the other code sample? I have Visual Studio 2010 Ultimate.

    The Usage shows how to use one of the several language extensions I provided so all you need is the one line to implement.

    The first one is a basic extension that saves the items to the desired text file and if it exists overwrite it while the second will append to an existing file. The remaining extensions are for when the ListBox has a DataTable as a DataSource and you want to save one column of data to a text file.


    KSG

    Wednesday, November 07, 2012 12:51 PM
    Moderator