C#檔案的分割與合并

標籤：c#   檔案   分割   合并   

        //--------------------檔案，分割與合并---------------------------------------- using System.IO        /// <summary>        /// 單個檔案分割函數,        /// 可將任意檔案fileIn分割為若干個子檔案， 單個子檔案最大為 len KB        /// delet標識檔案分割完成後是否刪除原檔案, change為加密密匙        /// fileIn = "D:\\file.rar", 子檔案名稱形如"D:\\[email protected]_1.split"        /// </summary>        public void fileSplit(String fileIn, int KBlen, bool delet, int change)        {            //輸入檔案校正            if (fileIn == null || !System.IO.File.Exists(fileIn))            {                MessageBox.Show("檔案" + fileIn + "不存在！");                return;            }            //加密初始化            short sign = 1;            int num = 0, tmp;            if (change < 0) { sign = -1; change = -change; }            //取檔案名稱和尾碼, fileIn = "D:\\1.rar"            //從檔案建立輸入資料流            FileStream FileIn = new FileStream(fileIn, FileMode.Open);            byte[] data = new byte[1024];   //流讀取,緩衝空間            int len = 0, I = 1;             //記錄子檔案累積讀取的KB大小, 分割的子檔案序號            FileStream FileOut = null;      //輸出資料流            int readLen = 0;                //每次實際讀取的位元組大小            while (readLen > 0 || (readLen = FileIn.Read(data, 0, data.Length)) > 0) //讀取資料            {                //建立分割後的子檔案，已有則覆蓋，子檔案"D:\\[email protected]_1.split"                if (len == 0) FileOut = new FileStream(fileIn + "@_" + I++ + ".split", FileMode.Create);                //加密邏輯,對data的首位元組進行邏輯位移加密                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;                //輸出，快取資料寫入子檔案                FileOut.Write(data, 0, readLen);                FileOut.Flush();                //預讀下一輪快取資料                readLen = FileIn.Read(data, 0, data.Length);                if (++len >= KBlen || readLen == 0)     //子檔案達到指定大小，或檔案已讀完                {                    FileOut.Close();                    //關閉當前輸出資料流                    len = 0;                }            }            FileIn.Close();                             //關閉輸入資料流            if (delet) System.IO.File.Delete(fileIn);   //刪除源檔案        }

        /// <summary>        /// 對多個檔案進行分割操作        /// </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("檔案分割完成！");        }

        /// <summary>        /// 檔案合并函數,        /// 可將任意個子檔案合并為一個,為fileSplit()的逆過程        /// delet標識是否刪除原檔案, change對data的首位元組進行解密        /// </summary>        public void fileCombine(String[] fileIn, bool delet, int change)        {            //輸入檔案名稱校正            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; }            //從首個子檔案解析原檔案名稱, fileIn[0] = "D:\\[email protected]_1.split"                        string name = fileIn[0];            int i1 = name.LastIndexOf("@_"), i2 = name.LastIndexOf('.');            name = name.Substring(0, i2);                                   //剔除子檔案拓展名".split"            string fileOut = (i1 == -1) ? name : name.Remove(i1, i2 - i1);  //剔除"@_1" -> "D:\\1.rar.split"                                  //建立輸出檔案，已有則覆蓋            FileStream FileOut = new FileStream(fileOut, FileMode.Create);            for (int i = 0; i < fileIn.Length; i++)            {                //輸入檔案校正                if (fileIn[i] == null || !System.IO.File.Exists(fileIn[i])) continue;                //從子檔案建立輸入資料流                FileStream FileIn = new FileStream(fileIn[i], FileMode.Open);                byte[] data = new byte[1024];   //流讀取,緩衝空間                int readLen = 0;                //每次實際讀取的位元組大小                while ((readLen = FileIn.Read(data, 0, data.Length)) > 0)       //讀取資料                {                    //解密邏輯,對data的首位元組進行邏輯位移解密                    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;                    //輸出，快取資料寫入檔案                    FileOut.Write(data, 0, readLen);                    FileOut.Flush();                }                //關閉輸入資料流，刪除源檔案                FileIn.Close();                if (delet) System.IO.File.Delete(fileIn[i]);            }            FileOut.Close();    //關閉輸出資料流        }

        /// <summary>        /// 對多組子檔案進行合并        /// </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("檔案合并完成！");        }

C#檔案的分割與合并