Copy only new or modified files/directories in C#

Question

I know this has probably been done and discussed umpteen times, but I can’t find the answer I am looking for.

I am trying to create a simple “directory/file copy" console application in C#.

What I need is to copy all folders and files (keeping the original hierarchy) from one drive to another, like from drive C:\Data to drive E:\Data.

However, I only want it copy any new or modified folders and files. If the folder or file on the destination drive is newer than the one on the source drive, then it does not copy.

Here is the code I have tried, but it’s not working. Any suggestions? Thank you. 

class Copy
{
    public static void CopyDirectory(DirectoryInfo source, DirectoryInfo destination)
    {
        if (!destination.Exists)
        {
            destination.Create();
        }
        // Copy files.
        FileInfo[] files = source.GetFiles();
        FileInfo[] destFiles = destination.GetFiles();
        foreach (FileInfo file in files)
            foreach (FileInfo fileD in destFiles)
                // Copy only modified files
                if (file.Exists)
                {
                    if (file.LastWriteTime > fileD.LastWriteTime)
                    {
                        file.CopyTo(Path.Combine(destination.FullName,
                        file.Name), true);
                    }
                }
                // Copy all new files
                else
                if (!fileD.Exists)
                {
                    file.CopyTo(Path.Combine(destination.FullName, file.Name), true);
                }
        // Process subdirectories.
        DirectoryInfo[] dirs = source.GetDirectories();
        foreach (DirectoryInfo dir in dirs)
        {
            // Get destination directory.
            string destinationDir = Path.Combine(destination.FullName, dir.Name);
            // Call CopyDirectory() recursively.
            CopyDirectory(dir, new DirectoryInfo(destinationDir));
        }
    }
}