Binary To Decimal Converter (Console App)

'------------------------------------------------------------------------------------------
'           Notice of My Copyright and Intellectual Property Rights
'
' Any intellectual property contained within the program by Joseph L. Bolen remains the
' intellectual property of the Joseph L. Bolen. This means that no person may distribute,
' publish or provide such intellectual property to any other person or entity for any
' reason, commercial or otherwise, without the express written permission of Joseph L. Bolen.
'
'                 Copyright © 2017. All rights reserved.
'        All trademarks remain the property of their respective owners.
'-------------------------------------------------------------------------------------------
' Program Name:   Binary to Decimal Converter
'
' Author:         Joseph L. Bolen
' Date Created:   27 JUN 2017
'
' Description:    Visual Basic Console app to convert a binary string into a
'                 decimal value.

'                 Documentation is at:
'                   App's Visual Basic .NET code is at https://pastebin.com/J2Ch9cb8
'                   Video tutorial at YouTube: http://www.youtube.com/user/bolenpresents
'-------------------------------------------------------------------------------------------

Module MainLIne

    Sub Main()

        ' Set Console attributes.
        Console.Title = "Binary to Decimal Converter"

        Console.ForegroundColor = ConsoleColor.Yellow
        Console.BackgroundColor = ConsoleColor.Blue
        Console.Clear()

        ' Prime read
        Dim binaryInput As String = GetValidInput()

        Do Until String.IsNullOrWhiteSpace(binaryInput)
            Dim numericValue As Double = 0
            Dim binLength = binaryInput.Length

            For idx As Integer = 2 To binLength
                If binaryInput.Substring(binLength - idx, 1) = "1" Then
                    numericValue += (2 ^ (idx - 1))
                End If
            Next

            If binaryInput.Substring(binLength - 1, 1) = "1" Then
                numericValue += 1
            End If

            Console.WriteLine("Decimal value is: {0}", numericValue.ToString)
            Console.WriteLine()
            binaryInput = GetValidInput()
        Loop
    End Sub

    Private Function GetValidInput() As String
        Dim input As String = String.Empty
        Dim validData As Boolean

        Do
            validData = True
            Console.WriteLine("Press [Enter] key to exit or ...")
            Console.Write("Enter a binary string to be converted to decimal value: ")
            input = Console.ReadLine()
            For idx As Integer = 0 To input.Length - 1
                Dim tempString As String = input.Substring(idx, 1)
                If tempString <> "0" AndAlso tempString <> "1" Then
                    Console.WriteLine("Enter only 0's and 1's. Try again.")
                    Console.WriteLine()
                    validData = False
                    Exit For
                End If
            Next
        Loop Until validData
        Return input
    End Function
End Module