C# FileStream CopyToAsync(Stream, Int32)

[ComVisibleAttribute(false)]//w  w  w.j a  v a2 s. c  o m
[HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)]
public Task CopyToAsync(
  Stream destination,
  int bufferSize
)

using System;//from   w ww .j a  va 2 s  .com
using System.Threading.Tasks;
using System.Windows;
using System.IO;

public class MainWindow 
{
    public static void Main(){}
    public MainWindow()
    {
        string StartDirectory = @"c:\start";
        string EndDirectory = @"c:\end";

        foreach (string filename in Directory.EnumerateFiles(StartDirectory))
        {
            using (FileStream SourceStream = File.Open(filename, FileMode.Open))
            {
                using (FileStream DestinationStream = File.Create(EndDirectory + filename.Substring(filename.LastIndexOf('\\'))))
                {
                    await SourceStream.CopyToAsync(DestinationStream,200);
                }
            }
        }
    }
}