using System;using System.Collections.Generic;using System.Text;using System.IO;

namespace RocketStudio{class ShredFile    {/// <summary>/// 文件粉碎选项/// </summary>        public enum ShredMode        {/// <summary>/// 随机数/// </summary>            RandData,/// <summary>/// 指定的Byte/// </summary>            UserByte,/// <summary>/// 指定的字符串/// </summary>            UserString        }/// <summary>/// 将指定的流粉碎使用随机数/// </summary>/// <param name="fs">文件流</param>/// <returns></returns>        public bool Shred(FileStream fs)        {try            {                BinaryWriter bw = new BinaryWriter(fs);long fileLength = fs.Length;long writeBytes = 0;                Random random = new Random();byte[] data = new byte[10240];                random.NextBytes(data);

for (; writeBytes < fileLength; writeBytes += 10240)                {if (fileLength - writeBytes > 10240)                        bw.Write(data);else bw.Write(data, 0, (int)(fileLength - writeBytes));                }                fs.Flush();return true;            }catch            {return false;            }        }/// <summary>/// 将指定的流粉碎使用指定字符/// </summary>/// <param name="fs">文件流</param>/// <param name="data">字符串</param>/// <returns></returns>        public bool Shred(FileStream fs, byte data)        {try            {                BinaryWriter bw = new BinaryWriter(fs);long fileLength = fs.Length;long writeBytes = 0;for (; writeBytes < fileLength; writeBytes++)                {                    bw.Write(data);                }                fs.Flush();return true;            }catch            {return false;            }        }/// <summary>/// 将指定的流粉碎使用指定字符串/// </summary>/// <param name="fs">文件流</param>/// <param name="data">字符串</param>/// <returns></returns>        public bool Shred(FileStream fs, string data)        {try            {                BinaryWriter bw = new BinaryWriter(fs);long fileLength = fs.Length;long writeBytes = 0;char[] dataArry = new char[data.Length];for (int ii = 0;ii<data.Length;ii++)                {                    dataArry[ii] = data[ii];                }int dataLength = dataArry.Length;for (; writeBytes < fileLength; writeBytes += dataLength)                {if ((fileLength - writeBytes) < dataLength)                        bw.Write(dataArry);else bw.Write(dataArry, 0, dataLength);                }                fs.Flush();return true;            }catch            {return false;            }        }public void RenameFile(string old, string last)        {            File.Move(old, last);        }/// <summary>/// 使用随机数生成文件名/// </summary>/// <returns></returns>        private string ReandName()        {            Random random = new Random();            random.Next(1000).ToString();return random.Next(1000).ToString() + random.Next(1000).ToString() + random.Next(1000).ToString();        }/// <summary>/// 开始粉碎/// </summary>/// <param name="fileName">文件名</param>/// <param name="data">填充数据，ShredMode.RandData 将忽略 可为NULL</param>/// <param name="sm">粉碎文件模式</param>/// <returns>是否成功</returns>        public bool StartShredFile(string fileName, object data, ShredMode sm, bool IsCleanCreatedDate, bool IsCleanLastUsedDate, bool IsCleanName, bool IsEmptyFile)         {            FileStream fs = null;try            {                fs = File.Open(fileName, FileMode.Open);            }catch            {//error                return false;            }bool IsSucceed = false;switch (sm)            {case ShredMode.RandData:                    IsSucceed = Shred(fs);break;case ShredMode.UserByte:                    IsSucceed = Shred(fs, Convert.ToByte(data));break;case ShredMode.UserString:                    IsSucceed = Shred(fs, (string)data);break;

            }            DateTime dt = new DateTime(2012,12,24);try            {                FileInfo fi = new FileInfo(fileName);string randName;if (IsCleanName)                    randName = ReandName();else randName = @"\"+fi.Name;

                fs.Close();if(IsEmptyFile)                File.Open(fi.FullName, FileMode.Truncate).Close();if(IsCleanName)                RenameFile(fi.FullName, fi.DirectoryName + randName);if(IsCleanCreatedDate)                File.SetCreationTime(fi.DirectoryName + randName, dt);if (IsCleanLastUsedDate)                {if(IsCleanName)                      File.SetLastWriteTime(fi.DirectoryName + randName, dt);else                        File.SetLastWriteTime(fi.FullName, dt);                }                File.Delete(fi.DirectoryName + randName);            }

catch            {return false;            }finally { fs.Close(); }return IsSucceed;        }    }

}