trying to create a search button for my listbox

[AA123]

hello to all i am practicing creating a data file using streamwriter/reader. I am a beginner and what i am trying to do is create a data file and create a search button that will be able to search the data file and show in the listbox the item or items searched for.

this is my code. i tried also using FindExactString method but i just cant seem to be able to do it. i dont get how to use or write it correctly. any help would be appreciated thank you in advance.

Imports System.IO
Public Class Form1


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim pInventory As IO.StreamWriter = IO.File.AppendText("product.txt")
        If TextBox1.Text = "" Or TextBox2.Text = "" Or TextBox3.Text = "" Then
            MsgBox("Please fill in required fields", MsgBoxStyle.Exclamation, "Error")
        Else
            pInventory.WriteLine(TextBox1.Text & ", $" & TextBox2.Text & ", " & TextBox3.Text)
            TextBox1.Clear()
            TextBox2.Clear()
            TextBox3.Clear()
            Dim num As Integer
            For num = 0 To ListBox1.Items.Count - 1
                pInventory.WriteLine(ListBox1.Items(num))
            Next
            pInventory.Close()
        End If
    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
      Dim name As String
        Dim num As Integer
        Dim max As Integer
name = InputBox("Enter a search word", "Search")
        num = 0
        max = ListBox1.Items.Count - 1
        'ListBox1.Items.Add(ListBox1.Items.Item(0))
        Do While (name <> (ListBox1.Items.Item(num))) And (num < max) **i keep getting an error in this line**
            num = num + 1

            ListBox1.Items.Add(num)
        Loop
        If (name = ListBox1.Items.Item(num)) Then
MsgBox(name & " Was found", , "Search")
        Else
MsgBox(name & " Was not found", , "Search")
        End If
end sub
end class

[jmcilhinney]

Firstly, if n error occurs, please tell us what the error message is, not just that an error occurs, so that we know what we're looking for.

As for the question, what is it that you're actually trying to achieve? Are you saying that you want to read the lines of a file and populate a ListBox with the line numbers of those that match some text entered by the user? Rather than just a general description, please tell us EXACTLY what it is that you want to happen rather than our having to work it out from code that doesn't actually do it.

[dunfiddlin]

Do While (name <> (ListBox1.Items.Item(num))) And (num < max) **i keep getting an error in this line**
            num = num + 1
 
            ListBox1.Items.Add(num) ' what?
        Loop

So if you find a matching item in the Listbox add it's number to the Listbox items making what presumably is a long list (otherwise why have a search facility at all) even longer? How does that make any sense?

Do you have Option Strict On because that would certainly raise an error on that line because of all the implicit conversions required. I would probably use a For Each loop here and simply select any matches within the ListBox but then I'm really not sure what you're actually doing this for in the first place. What happens when you've found the item? The fact that it's in a ListBox means that there aren't really a lot of options going forward from that point.

[AA123]

OK, sorry about that. well firstly the error that i get is "exception was unhandled. it says its an invalid argument."
I want the search button that i am creating to show the keyword searched for in the listbox. FOR EXAMPLE if i search for STREAMREADER then all the words with stream and reader will appear in the listbox like......STREAMwriter, STREAM, READERfile, etc. i know i have an example there that adds items to the listbox but its the only thing i have to work with. its from a previous assignment that i had to do and im trying to change things up but i cant figure it out, i tried using FindString but obviously im doing something wrong i figured i would work from my homework example again. see i am creating four buttons in total:
1. an entry data button that saves words in a txt file.
2. a view data button that shows all of the data entered into the txt file.
3. a delete data button that deletes a selected word from the listbox.
and
4. a search data button that searches the txt file for words that may or may not exist in the text file...........this is the only one im having problems with. i was having problems with the view data button but i kept working and looking up information and finally figured it out but that damn search button i cant seem to get it...

[jmcilhinney]

FOR EXAMPLE if i search for STREAMREADER then all the words with stream and reader will appear in the listbox like......STREAMwriter, STREAM, READERfile, etc.

Does that really make sense? That was rhetorical question; it doesn't make sense. How exactly is the program supposed to know that it's OK to break that search term up as "stream" and "reader" rather than "str" and "eamreader" or any other combination? Do you actually mean that you would enter the text "stream reader" and they would be treated as separate keywords because of the space? Please tell us what you actually mean so that we don't have to guess or, if you really did mean what you posted earlier, rethink things because that isn't logical.

[AA123]

How exactly is the program supposed to know that it's OK to break that search term up as "stream" and "reader" rather than "str" and "eamreader" or any other combination? Do you actually mean that you would enter the text "stream reader" and they would be treated as separate keywords because of the space?

what i meant was: if somebody searches for streamreader all of the words that have streamreader in them will show up in the listbox. for example: if i search for streamreader and there is a word like helloiamSTREAMREADERhowareyou then this entire "word" ,helloiamSTREAMREADERhowareyou, will show up in the listbox. i am just trying to create a search method for my program. you search for a keyword and if it is in the text file then it will show up in the listbox. sorry i guess im so frustrated with this that i didnt realize how i worded my msg.

[ident]

what i meant was: if somebody searches for streamreader all of the words that have streamreader in them will show up in the listbox. for example: if i search for streamreader and there is a word like helloiamSTREAMREADERhowareyou then this entire "word" ,helloiamSTREAMREADERhowareyou, will show up in the listbox. i am just trying to create a search method for my program. you search for a keyword and if it is in the text file then it will show up in the listbox. sorry i guess im so frustrated with this that i didnt realize how i worded my msg.

Whats your idea of the word meaning exact?

Finds the first item in the ListBox that exactly matches the specified string.

helloiamSTREAMREADERhowareyou does not EXACTLY match streamreader does it.

[AA123]

Whats your idea of the word meaning exact?

Finds the first item in the ListBox that exactly matches the specified string.

helloiamSTREAMREADERhowareyou does not EXACTLY match streamreader does it.

what the hell are you talking about i didnt mention anything about exact.

[ident]

Are you sure "i tried also using FindExactString method but i just cant seem to be able to do it."