[c#] How do I create a file AND any folders, if the folders don't exist?

Following code will create directories (if not exists) & then copy files.

// using System.IO;

// for ex. if you want to copy files from D:\A\ to D:\B\
foreach (var f in Directory.GetFiles(@"D:\A\", "*.*", SearchOption.AllDirectories))
{
    var fi =  new FileInfo(f);
    var di = new DirectoryInfo(fi.DirectoryName);

    // you can filter files here
    if (fi.Name.Contains("FILTER")
    {
        if (!Directory.Exists(di.FullName.Replace("A", "B"))
        {                       
            Directory.CreateDirectory(di.FullName.Replace("A", "B"));           
            File.Copy(fi.FullName, fi.FullName.Replace("A", "B"));
        }
    }
}