How to transfer data from listbox to textbox in Visual Basic - vb.net

Question

I did some activity but I cant figure out how to retrieve data from listbox1 to textbox1. Example in the listbox1 there are 4 names: John, Jorge, Joe. Then I want to transfer Joe from listbox1 to textbox1. I did an arraylist where I adding those 3 names in the listbox1 but I didn't know how to retrieve the name "Jorge" from listbox1 to textbox1. Send help.
Here's the code where I try to retrieve one of the name from listbox1 to textbox1
Private Sub Retrievebtn_Click(sender As Object, e As EventArgs) Handles Retrievebtn.Click
If textbox1.Text = ListBox1.Items.Count Then
textbox1.Text = ArrayofNames(x)
End If
End Sub
Here's the whole code
Public Class Form1
Dim ArrayofNames() As String
Dim x As Integer
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Retrievebtn_Click(sender As Object, e As EventArgs) Handles Retrievebtn.Click
If textbox1.Text = ListBox1.Items.Count Then
textbox1.Text = ArrayofNames(x)
End If
End Sub
Private Sub Addbtn_Click(sender As Object, e As EventArgs) Handles Addbtn.Click
Dim x As Integer = 0
ReDim ArrayofNames(x)
For x = 0 To ArrayofNames.Length - 1
ArrayofNames(x) = Addtextbox.Text
ListBox1.Items.Add(ArrayofNames(x))
Next
End Sub
Private Sub removeBtn_Click(sender As Object, e As EventArgs) Handles removeBtn.Click
ListBox1.Items.Remove(ListBox1.SelectedItem)
End Sub
End Class
Here's the Image of the interface i try to retrieve the name Joe but it wasn'tshowing

Answer 1

Let's go over the code you posted.
In the retrieve button click event you are comparing and Integer to a String with textbox1.Text = ListBox1.Items.Count This won't compile with Option Strict On. You do have Option Strict On, don't you? You should always have this on.
On the next line, you assign the value of ArrayofNames(x), where x refers to your form level variable, to a text box's Text property. Since the value of x is never changed anywhere in the code this will always return the 0 index in the array. (The first element) I can't imagine why it should matter that the Textbox.Text should equal the count of the ListBox items.
In the add button click event you first declare a local variable x. Any code in the method will use this x, not the form level x. You ReDim (without the Preserve keyword) the array to an array with a single element. Your For loop is silly because the length of ArrayofNames is 1, so it is 0 To 0.
The ArrayofNames will never have more than a single element and it will be overwritten each time the add button is clicked.
Fortunately the Listbox maintains its own collection of items.
We can use this collection to simplify your code. Just add the contents of the text box to the the list items.
To retrieve a value from the list box you must first determine if the user has entered a valid index. First, is the entry a valid Integer and is it an index present in the list box.
Remember that .net collections start at index 0.
I use default names in my test program but you should continue to use meaningful names for your controls.
'Your add button
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim index As Integer
If Integer.TryParse(TextBox1.Text, index) AndAlso index >= 0 AndAlso ListBox1.Items.Count - 1 >= index Then
TextBox2.Text = ListBox1.Items(index).ToString
End If
End Sub
'Your add button
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
ListBox1.Items.Add(TextBox3.Text)
End Sub