[RESOLVED] VS.NET 2015 getting System.NullReferenceExcept while trying to transfer Strings

[Haider92]

Hi Everyone

I'm trying to use Visual Basic.net 2015 to programming app to use it to split data logger record and store in into array, then use any operations with them...

but the problem is when i try to transfer string between variable i get an error

sell the source code below.

Imports System.Text
Imports System.IO
Public Class Form1
    Dim path As String = Nothing
    Dim splited() As String
    Dim buffer() As String
    Dim truec() As String
    Dim ic As Integer
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim FileReader As StreamReader
        Dim results As DialogResult
        results = OpenFileDialog1.ShowDialog
        If results = DialogResult.OK Then
            FileReader = New StreamReader(OpenFileDialog1.FileName)
            Document.Text = FileReader.ReadToEnd()
            FileReader.Close()

        End If
    End Sub

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button2.Click
        ic = 0
        splited = Document.Text.Split(";")
        MsgBox(splited.Count)
        MsgBox(splited(4))
        buffer = splited(0).Split(",")
        Label1.Text = buffer(0)
        Label2.Text = buffer(1)
        For i As Integer = 0 To splited.Count - 2
            buffer = splited(i).Split(",")
            If buffer(0) = "ROOM_ON" Then
                MsgBox(buffer(1))
                truec(0) = buffer(1)
                ic = ic + 1
            End If
        Next i

    End Sub
End Class

the source code in the attachment contain vb.net source code and text file

[jmcilhinney]

You never create the 'truec' array. You declare the variable but you never create an array object and assign it to the variable.

[Haider92]

You never create the 'truec' array. You declare the variable but you never create an array object and assign it to the variable.

can you give me a code fix for this?

[Haider92]

If I declare 'truec' like
Dim truce(100) as string
there will be no problem and the program fun fine but if I remove the 100 from the truce I'll get the same error why, I want to make an array with out declare it's size like Dim splited() As String, and I use it.

[techgnome]

You HAVE to give it a size at some point... or it doesn't exist. splitted() works because the Split function will resize the array and fill it. You need to do the same with truec array... you have to give it a size at some point, so the memory can be allocated and used.

I only see one index of truec being used - truec(0) ... is that the only index that's used? if that's the case, it doesn't need to be an array. If there are other indicies used... well... then yes, it needs to be an array.

-tg

[Haider92]

Thank you very much, I solve it after giving it a size.