Trying to add a list of suppliers in an array and then i am adding it to listbox and combobox using `.addrange` but i am receiving error - vb.net

Question

I retrieved list of suppliers from database and saved it in an array TOTAL_SUPPLIERS_ARRAY NOW i am trying it to add in the listbox or combobox but it shows an error on runtime saying "VALUE CAN NOT BE NULL" but if i try to add it with an loop it works properly why is it not working with .addrange ?
Sub GET_SUPPLIERS_DETAILS()
Dim CON As New MySqlConnection("server=localhost; username=root; password=Masoom1; database=airtech_db;")
Dim cmd As New MySqlCommand("Select * from `Suppliers`;", CON)
Dim da As New MySqlDataAdapter("Select * from `Suppliers`;", CON)
Dim ds As New DataSet
Dim dr As MySqlDataReader
Dim TOTAL_SUPPLIERS As Integer
CON.Open()
da.Fill(ds)
dr = cmd.ExecuteReader
TOTAL_SUPPLIERS = ds.Tables(0).Rows.Count
Dim TOTAL_SUPPLIERS_ARRAY(TOTAL_SUPPLIERS) As String, ARRAYINDEX As Integer
Do While dr.Read() = True
TOTAL_SUPPLIERS_ARRAY(ARRAYINDEX) = dr("Supplier_Name").ToString()
ARRAYINDEX += 1
Loop
CON.Close()
Dim cbCell As New DataGridViewComboBoxCell
For k = 0 To DataGridView1.Rows.Count - 1
cbCell = DataGridView1.Rows(k).Cells("Supplier_Name")
For iIndex = 0 To UBound(TOTAL_SUPPLIERS_ARRAY) - 1
cbCell.Items.Add(TOTAL_SUPPLIERS_ARRAY(iIndex))
Next
Next
ListBox1.Items.AddRange(TOTAL_SUPPLIERS_ARRAY)
ComboBox1.Items.AddRange(TOTAL_SUPPLIERS_ARRAY)
For I As Integer = 0 To UBound(TOTAL_SUPPLIERS_ARRAY) - 1
TextBox1.Text += TOTAL_SUPPLIERS_ARRAY(I) & " - "
Next I
End Sub
This part works only as i added it through a loop
For I As Integer = 0 To UBound(TOTAL_SUPPLIERS_ARRAY) - 1
TextBox1.Text += TOTAL_SUPPLIERS_ARRAY(I) & " - "
Next I
listbox.addrange command and combobox.addrange command not working

Answer 1

Here you have an issue TOTAL_SUPPLIERS_ARRAY(TOTAL_SUPPLIERS). Array declared in VB - array(upper-bound). Upper bound is 1 less than count. So, you should do TOTAL_SUPPLIERS_ARRAY(TOTAL_SUPPLIERS - 1).
But why struggle? Just use list
Dim myList as New List(of String)
While dr.Read()
myList.Add(dr("Supplier_Name").ToString())
Loop
And then, if you still need array, you can use LINQ - myList.ToArray
ListBox1.DataSource = myList.ToArray()