Hi,
I am looking for some guidance to understand arraylists versus string lists. I had an old application where I had all my arrays as arraylists. I am working on another application and decided to use List(of string) instead.
I keep getting (System.NullReferenceException: 'Object reference not set to an instance of an object.') errors, when I try to add a value to my string array or clear it.
I read that I need to redefine it as a new list(of string) before using it to initiate it and prevent the null error. the issue is I don't want to lose the values on the array, as I use it in other forms. I don't get those errors with arraylist. Is there a way to disable this exception or what is the best way to use string list.
I am looking for some guidance to understand arraylists versus string lists. I had an old application where I had all my arrays as arraylists. I am working on another application and decided to use List(of string) instead.
I keep getting (System.NullReferenceException: 'Object reference not set to an instance of an object.') errors, when I try to add a value to my string array or clear it.
Code:
Public Class Main_Frm
Public Imported_IDS, ProductNo As List(Of String)
Private Sub Start_Btn_Click(sender As Object, e As EventArgs) Handles Start_Btn.Click
Imported_IDS.Clear()
ProductNo.Clear()
Imported_IDS.Add(Trim(textbox1.text))
ProductNo.add(textbox2.text))
end sub
end sub