C#自适应合并文件的方法

using System;
using System.IO;
namespace MergeFile
{
  class Program
  {
    public static void Main(string[] args)
    {
      int count=1;
      string sourcepath=@"D:\SplitFile";
      string filetomerge=@"C:\编程的奥秘.pdf";
      FileStream ftm = new FileStream(filetomerge, FileMode.Create, FileAccess.Write);
      BinaryWriter bw=new BinaryWriter(ftm);
      string filepath;
      while(File.Exists(filepath=sourcepath+Path.DirectorySeparatorChar+Path.GetFileName(filetomerge)+count++))
      {
        FileStream fsr = new FileStream(filepath, FileMode.Open, FileAccess.Read);
        BinaryReader br=new BinaryReader(fsr);
        bw.Write(br.ReadBytes((int)fsr.Length));
        br.Close();
        fsr.Close();
      }
      bw.Flush();
      bw.Close();
      ftm.Close();
    }
  }
}