//--------------------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:\\[email protected]_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:\\[email protected]_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:\\[email protected]_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！");
}
时间： 2024-08-28 17:08:30