using System;using System.IO;string filetomerge=@"C:/temp/data.bin";string targetpath=@"D:/store";string strFileName = filetomerge.Substring(filetomerge.LastIndexOf(Path.DirectorySeparatorChar) + 1);FileStream fsr1 = new FileStream(targetpath+ Path.DirectorySeparatorChar + strFileName + "1", FileMode.Open, FileAccess.Read);FileStream fsr2 = new FileStream(targetpath+ Path.DirectorySeparatorChar + strFileName + "2", FileMode.Open, FileAccess.Read);byte[] btArr = new byte[fsr1.Length+fsr2.Length];fsr1.Read(btArr, 0, Convert.ToInt32(fsr1.Length));fsr2.Read(btArr, Convert.ToInt32(fsr1.Length), Convert.ToInt32(fsr2.Length));fsr1.Close();fsr2.Close();FileStream fsw = new FileStream(%%2 + Path.DirectorySeparatorChar+ strFileName, FileMode.Create, FileAccess.Write);fsw.Write(btArr, 0, btArr.Length);fsw.Flush();fsw.Close();