学步园

namespace FS
{
    public class FileSplitter
    {
        private enum MSG 
        {
            FILE_NOT_EXIST          = 1,
            DIR_NOT_EXIST           = 2,
            BLOCKSIZE_ERROR         = 3,
            BLOCKSIZE_TOO_LARGE     = 4,
            BLOCKSIZE_TOO_SMALL     = 5,
            CAN_NOT_OPEN_FILE       = 6,
            CAN_NOT_CREATE_FILE     = 7,
            CAN_NOT_CREATE_CMDFILE  = 8
        };
        private string m_srcPath;
        private string m_destDir;
        private long m_nBlockSize = 0;
        private MSG m_byError = 0;

        public FileSplitter(string srcPath)
        {
            m_srcPath = srcPath;
            m_destDir = Path.GetDirectoryName(m_srcPath);
        }

        public FileSplitter(string srcPath, string destDir)
        {
            m_srcPath = srcPath;
            m_destDir = destDir;
        }

        public FileSplitter(string srcPath, long nBlockSize)
        {
            m_srcPath = srcPath;
            m_destDir = Path.GetDirectoryName(m_srcPath);
            m_nBlockSize = nBlockSize;
        }

        public FileSplitter(string srcPath, string destDir, long nBlockSize)
        {
            m_srcPath = srcPath;
            m_destDir = destDir;
            m_nBlockSize = nBlockSize;
        }

        public bool SplitFile()
        {
            if (!File.Exists(m_srcPath))
            {
                m_byError = MSG.FILE_NOT_EXIST;
                return false;
            }

            if (!Directory.Exists(m_destDir))
            {
                m_byError = MSG.DIR_NOT_EXIST;
                return false;
            }

            FileInfo fi = new FileInfo(m_srcPath);

            if (m_nBlockSize == 0)
            {
                m_nBlockSize = fi.Length;
            }

            if (m_nBlockSize <= 0)
            {
                m_byError = MSG.BLOCKSIZE_ERROR;
                return false;
            }

            if (m_nBlockSize >= fi.Length)
            {
                m_byError = MSG.BLOCKSIZE_TOO_LARGE;
                return false;
            }

            if (fi.Length / m_nBlockSize > 999)
            {
                m_byError = MSG.BLOCKSIZE_TOO_SMALL;
                return false;
            }

            FileStream fs_in;
            try
            {
                fs_in = new FileStream(m_srcPath, FileMode.Open);
            }
            catch
            {
                m_byError = MSG.CAN_NOT_OPEN_FILE;
                return false;
            }

            long file_rest = fi.Length ;
            string temp = "COPY /B ";
            int index = 1;
            byte[] bytes = new byte[1024];
            

            while (file_rest > 0)
            {
                string index_ext = "00" + index.ToString();
                FileStream fs_out;
                try
                {
                    fs_out = new FileStream(m_destDir + "//" + fi.Name + "." + index_ext.Substring(index_ext.Length - 3), FileMode.Create);
                }
                catch 
                {
                    m_byError = MSG.CAN_NOT_CREATE_FILE;
                    return false;
                }
                temp += "/"" + fi.Name + "." + index_ext.Substring(index_ext.Length - 3) + "/" + ";
                long block_rest;
                
                if(file_rest > m_nBlockSize )
                {
                    block_rest = m_nBlockSize;
                }
                else
                {
                    block_rest = file_rest;
                }

                file_rest -= block_rest;

                while (block_rest > 0)
                {
                    int count;

                    if (block_rest > 1024)
                    {
                        count = 1024;
                    }
                    else
                    {
                        count = (int)block_rest;
                    }

                    block_rest -=count;

                    fs_in.Read(bytes, 0, count);
                    fs_out.Write(bytes, 0, count);

                fs_out.Close();
                index++;
            }

            temp = temp.Substring(0, temp.Length - 2) + "/"" + fi.Name + "/"";

            StreamWriter sw_cmd;
            try
            {
                sw_cmd = new StreamWriter(m_destDir + "//join.cmd", false, Encoding.Default);
            }
            catch
            {
                m_byError = MSG.CAN_NOT_CREATE_CMDFILE;
                return false;
            }
            sw_cmd.WriteLine("@echo off");
            sw_cmd.WriteLine("cls");
            sw_cmd.WriteLine("echo 溪流文件分割 v6.0");
            sw_cmd.WriteLine("echo Copyright(C) 1998-2007 溪流软件工作室");
            sw_cmd.WriteLine("echo.");
            sw_cmd.WriteLine("");
            sw_cmd.WriteLine(":CheckFile");
            sw_cmd.WriteLine("echo 正在检测文件...");
            sw_cmd.WriteLine("echo.");
            sw_cmd.WriteLine("IF EXIST /"" + fi.Name + "/" GOTO FileAlreadyExist");
            sw_cmd.WriteLine("GOTO JoinFiles");
            sw_cmd.WriteLine("");
            sw_cmd.WriteLine(":FileAlreadyExist");
            sw_cmd.WriteLine("echo “" + fi.Name + "”已经存在，进行合并将覆盖文件。");
            sw_cmd.WriteLine("echo 要继续进行合并的话，请将“FileName”改名、");
            sw_cmd.WriteLine("echo 转移或删除。");
            sw_cmd.WriteLine("GOTO End");
            sw_cmd.WriteLine("");
            sw_cmd.WriteLine(":JoinFiles");
            sw_cmd.WriteLine("echo.");
            sw_cmd.WriteLine("echo 正在合并文件...");
            sw_cmd.WriteLine(temp);
            sw_cmd.WriteLine("echo 成功合并了文件“" + fi.Name + "”。");
            sw_cmd.WriteLine("GOTO End");
            sw_cmd.WriteLine("");
            sw_cmd.WriteLine(":End");
            sw_cmd.WriteLine("echo.");
            sw_cmd.WriteLine("echo.");
            sw_cmd.WriteLine("pause");
            sw_cmd.WriteLine("echo on");
            sw_cmd.WriteLine("exit");
            sw_cmd.Close();

            return true;
        }