Option Strict On

​

Imports System

Imports System.Linq

Public Module Module1

​

    Public Sub Main()

        'Populate some text file for example purposes only

        IO.File.WriteAllLines("test.txt", {"34512340,plain brackets,0.50", "56756777,100mm bolts,0.20", "90673412,L-shaped brackets,1.20"})

        'Read the text file

        Dim lines() As String = IO.File.ReadAllLines("test.txt")

        'Get the amount that will be multiplied

        Dim amount As Double = -1

        Do

            Console.Write("Amount: ")

            If Not Double.TryParse(Console.ReadLine, amount) OrElse amount < 0 Then

                Console.WriteLine("Please enter a valid greater than or equal to 0.")

            End If

        Loop Until amount >= 0

​

        'Get the GTIN number

        Console.Write("GTIN: ")

        Dim GTIN As String = Console.ReadLine()

        'Loop through each line

        Dim totalLine As String = lines.FirstOrDefault(Function(l) l.Split(","c)(0) = GTIN)

            If Not String.IsNullOrWhiteSpace(totalLine) Then

                Console.WriteLine("Total: " & (Convert.ToDouble(totalLine.Split(","c)(2)) * amount))

            End If

​

        Console.WriteLine("Hello World")

    End Sub

End Module