Lectura de un archivo binario (2 - GIF) Ejercicio VB.Net - Curso de Programación Visual Basic

Imports System
Imports System.IO
Public Class GifFile
    Public Shared Sub Main()
        Dim data As Byte() = New Byte(4) {}
        Dim file As BinaryReader = New BinaryReader(File.Open("test.gif", FileMode.Open))

        For i As Integer = 0 To 5 - 1
            data(i) = file.ReadByte()
        Next

        file.Close()

        If data(0) = Convert.ToByte("G"c) AndAlso data(1) = Convert.ToByte("I"c) AndAlso data(2) = Convert.ToByte("F"c) AndAlso data(3) = Convert.ToByte("8"c) Then
            Console.WriteLine("Its a GIF8" & data(4))
        Else
            Console.WriteLine("It not gif file")
        End If
    End Sub
End Class