C#文件的分割与合并

来源：互联网发布：java mockito 编辑：程序博客网时间：2024/05/22 00:11

        //--------------------文件，分割与合并---------------------------------------- using System.IO        /// <summary>        /// 单个文件分割函数,        /// 可将任意文件fileIn分割为若干个子文件， 单个子文件最大为 len KB        /// delet标识文件分割完成后是否删除原文件, change为加密密匙        /// fileIn = "D:\\file.rar", 子文件名形如"D:\\file.rar@_1.split"        /// </summary>        public void fileSplit(String fileIn, int KBlen, bool delet, int change)        {            //输入文件校验            if (fileIn == null || !System.IO.File.Exists(fileIn))            {                MessageBox.Show("文件" + fileIn + "不存在！");                return;            }            //加密初始化            short sign = 1;            int num = 0, tmp;            if (change < 0) { sign = -1; change = -change; }            //取文件名和后缀, fileIn = "D:\\1.rar"            //从文件创建输入流            FileStream FileIn = new FileStream(fileIn, FileMode.Open);            byte[] data = new byte[1024];   //流读取,缓存空间            int len = 0, I = 1;             //记录子文件累积读取的KB大小, 分割的子文件序号            FileStream FileOut = null;      //输出流            int readLen = 0;                //每次实际读取的字节大小            while (readLen > 0 || (readLen = FileIn.Read(data, 0, data.Length)) > 0) //读取数据            {                //创建分割后的子文件，已有则覆盖，子文件"D:\\1.rar@_1.split"                if (len == 0) FileOut = new FileStream(fileIn + "@_" + I++ + ".split", FileMode.Create);                //加密逻辑,对data的首字节进行逻辑偏移加密                if (num == 0) num = change;                tmp = data[0] + sign * (num % 3 + 3);                if (tmp > 255) tmp -= 255;                else if (tmp < 0) tmp += 255;                data[0] = (byte)tmp;                num /= 3;                //输出，缓存数据写入子文件                FileOut.Write(data, 0, readLen);                FileOut.Flush();                //预读下一轮缓存数据                readLen = FileIn.Read(data, 0, data.Length);                if (++len >= KBlen || readLen == 0)     //子文件达到指定大小，或文件已读完                {                    FileOut.Close();                    //关闭当前输出流                    len = 0;                }            }            FileIn.Close();                             //关闭输入流            if (delet) System.IO.File.Delete(fileIn);   //删除源文件        }

        /// <summary>        /// 对多个文件进行分割操作        /// </summary>        public void fileSplit(String[] fileIn, int KBlen, bool delet, int change)        {            if (fileIn == null || fileIn.Length == 0) return;            for (int i = 0; i < fileIn.Length; i++)                fileSplit(fileIn[i], KBlen, delet, change);            MessageBox.Show("文件分割完成！");        }

        /// <summary>        /// 文件合并函数,        /// 可将任意个子文件合并为一个,为fileSplit()的逆过程        /// delet标识是否删除原文件, change对data的首字节进行解密        /// </summary>        public void fileCombine(String[] fileIn, bool delet, int change)        {            //输入文件名校验            if (fileIn == null || fileIn.Length == 0) return;            //加密初始化            short sign = 1;            int num = 0, tmp;            if (change < 0) { sign = -1; change = -change; }            //从首个子文件解析原文件名, fileIn[0] = "D:\\1.rar@_1.split"                        string name = fileIn[0];            int i1 = name.LastIndexOf("@_"), i2 = name.LastIndexOf('.');            name = name.Substring(0, i2);                                   //剔除子文件拓展名".split"            string fileOut = (i1 == -1) ? name : name.Remove(i1, i2 - i1);  //剔除"@_1" -> "D:\\1.rar.split"                                  //创建输出文件，已有则覆盖            FileStream FileOut = new FileStream(fileOut, FileMode.Create);            for (int i = 0; i < fileIn.Length; i++)            {                //输入文件校验                if (fileIn[i] == null || !System.IO.File.Exists(fileIn[i])) continue;                //从子文件创建输入流                FileStream FileIn = new FileStream(fileIn[i], FileMode.Open);                byte[] data = new byte[1024];   //流读取,缓存空间                int readLen = 0;                //每次实际读取的字节大小                while ((readLen = FileIn.Read(data, 0, data.Length)) > 0)       //读取数据                {                    //解密逻辑,对data的首字节进行逻辑偏移解密                    if (num == 0) num = change;                    tmp = data[0] + sign * (num % 3 + 3);                    if (tmp > 255) tmp -= 255;                    else if (tmp < 0) tmp += 255;                    data[0] = (byte)tmp;                    num /= 3;                    //输出，缓存数据写入文件                    FileOut.Write(data, 0, readLen);                    FileOut.Flush();                }                //关闭输入流，删除源文件                FileIn.Close();                if (delet) System.IO.File.Delete(fileIn[i]);            }            FileOut.Close();    //关闭输出流        }

        /// <summary>        /// 对多组子文件进行合并        /// </summary>        public void fileCombine(String[][] fileIn, bool delet, int change)        {            for (int i = 0; i < fileIn.Length; i++)                fileCombine(fileIn[i], delet, change);            MessageBox.Show("文件合并完成！");        }

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