Check multiple files in folder if exist without specific filenames VB.NET

Question

im doing an application that checks or compare if the files are existing in the backup folder from another folder. I can do it with declaring a specific file or an array. like this one.

" = file1.txt"
" = file2.txt"
"etc..."

but how about not having specific files or array?

this is my code:

Imports System.IO
Public Class Form3
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    check()
End Sub
Sub check()

    Dim src As String = "D:\test"
    Dim dest As String = "D:\test2"

    Dim srcdir As New DirectoryInfo(src)
    Dim destdir As New DirectoryInfo(dest)
    Dim srcfile As FileInfo() = srcdir.GetFiles
    Dim destfile As FileInfo() = destdir.GetFiles

    Dim fi As FileInfo

    For Each fi In srcfile
        If fi.Name = fi.Name(destfile) Then
            MsgBox("no new files")
        Else
            MsgBox("new files detected")
        End If
    Next

    For Each fi In srcfile
        File.Copy(fi.FullName, dest & fi.Name)
    Next

End Sub

Answer 1

Try this:

    Dim filesToCopy As New ArrayList()
    For Each Dir As String In System.IO.Directory.GetFiles(src) ' This will check every file from src or (D:\Test)
        Dim dirInfo As New System.IO.DirectoryInfo(Dir)
        If Not System.IO.File.Exists(dest & "\" & dirInfo.Name) Then 'This will check if the file from src exists in dest (D:\Test2)
            filesToCopy.Add(dirInfo.Name)
        End If
    Next

    If filesToCopy.Count > 0 Then
        If MsgBox("There are new files found. Do you want to sync it now?", MsgBoxStyle.Question + MsgBoxStyle.YesNo, "Confirm") = MsgBoxResult.Yes Then
            For i = 0 To filesToCopy.Count - 1
                System.IO.File.Copy(src & "\" & filesToCopy(i), dest & "\" & filesToCopy(i))
            Next
        End If
    End If

Edited so you can get the most of what you need.

Answer 2

try this u r code is working fine jst change the logic of it i alredy given in below code

Imports System.IO
    Public Class Form3
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        check()
    End Sub
    Sub check()

    Dim src As String = "D:\test"
    Dim dest As String = "D:\test2"

    Dim srcdir As New DirectoryInfo(src)
    Dim destdir As New DirectoryInfo(dest)
    Dim srcfile As FileInfo() = srcdir.GetFiles
    Dim destfile As FileInfo() = destdir.GetFiles

    Dim fi As FileInfo

    For Each fi In srcfile
        If If Not System.IO.File.Exists(fi.Name) Then 
            MsgBox("no new files")
            Exit sub
        Else
           For Each fi In srcfile
               File.Copy(fi.FullName, dest & fi.Name)
          Next
        End If
    Next



End Sub