C# GZipStream 压缩 解压

(转自：http://www.cnblogs.com/leiOOlei/archive/2011/06/15/2081514.html)      
关于GZipStream压缩解压，网上找了很多资料，完整的不多，要么是针对字符串压缩解压缩的，要么只实现了针对单个文件的压缩解压缩，还有的不支持子文件夹的压缩，实用性都不是很大。(我自己也写过一个类,功能都已经实现,但是感觉还是这个比较全面些。这篇虽然注释不多,但仔细看还是能看明白的。)

      以下整理了压缩解压缩的代码，供以后拿出来翻阅，在项目中可以直接使用这3个类，已通过测试。
      1.首先是有一个描述要压缩的文件类GZipFileInfo，包含了一些文件信息

/// <summary>
/// 要压缩的文件信息
/// </summary>
public class GZipFileInfo
{
/// <summary>
/// 文件索引
/// </summary>
public int Index = 0;
/// <summary>
/// 文件相对路径，'/'
/// </summary>
public string RelativePath = null;
public DateTime ModifiedDate;
/// <summary>
/// 文件内容长度
/// </summary>
public int Length = 0;
public bool AddedToTempFile = false;
public bool RestoreRequested = false;
public bool Restored = false;
/// <summary>
/// 文件绝对路径,'\'
/// </summary>
public string LocalPath = null;
public string Folder = null;

public bool ParseFileInfo(string fileInfo)
{
bool success = false;
try
{
if (!string.IsNullOrEmpty(fileInfo))
{
// get the file information
string[] info = fileInfo.Split(',');
if (info != null && info.Length == 4)
{
this.Index = Convert.ToInt32(info[0]);
this.RelativePath = info[1].Replace("/", "\\");
this.ModifiedDate = Convert.ToDateTime(info[2]);
this.Length = Convert.ToInt32(info[3]);
success = true;
}
}
}
catch
{
success = false;
}
return success;
}
}

      2.压缩后生成的压缩包信息GZipResult，描述了压缩包的一些属性，包括大小，文件数，以及其中的每一个文件

/// <summary>
/// 文件压缩后的压缩包类
/// </summary>
public class GZipResult
{
/// <summary>
/// 压缩包中包含的所有文件,包括子目录下的文件
/// </summary>
public GZipFileInfo[] Files = null;
/// <summary>
/// 要压缩的文件数
/// </summary>
public int FileCount = 0;
public long TempFileSize = 0;
public long ZipFileSize = 0;
/// <summary>
/// 压缩百分比
/// </summary>
public int CompressionPercent = 0;
/// <summary>
/// 临时文件
/// </summary>
public string TempFile = null;
/// <summary>
/// 压缩文件
/// </summary>
public string ZipFile = null;
/// <summary>
/// 是否删除临时文件
/// </summary>
public bool TempFileDeleted = false;
public bool Errors = false;
}

      3.压缩操作类GZip，包括压缩解压等操作

/// <summary>
/// 压缩文件类
/// </summary>
public class GZip
{
/// <summary>
/// Compress
/// </summary>
/// <param name="lpSourceFolder">The location of the files to include in the zip file, all files including files in subfolders will be included.</param>
/// <param name="lpDestFolder">Folder to write the zip file into</param>
/// <param name="zipFileName">Name of the zip file to write</param>
public static GZipResult Compress(string lpSourceFolder, string lpDestFolder, string zipFileName)
{
return Compress(lpSourceFolder, "*.*", SearchOption.AllDirectories, lpDestFolder, zipFileName, true);
}

/// <summary>
/// Compress
/// </summary>
/// <param name="lpSourceFolder">The location of the files to include in the zip file</param>
/// <param name="searchPattern">Search pattern (ie "*.*" or "*.txt" or "*.gif") to idendify what files in lpSourceFolder to include in the zip file</param>
/// <param name="searchOption">Only files in lpSourceFolder or include files in subfolders also</param>
/// <param name="lpDestFolder">Folder to write the zip file into</param>
/// <param name="zipFileName">Name of the zip file to write</param>
/// <param name="deleteTempFile">Boolean, true deleted the intermediate temp file, false leaves the temp file in lpDestFolder (for debugging)</param>
public static GZipResult Compress(string lpSourceFolder, string searchPattern, SearchOption searchOption,string lpDestFolder, string zipFileName, bool deleteTempFile)
{
DirectoryInfo di = new DirectoryInfo(lpSourceFolder);
FileInfo[] files = di.GetFiles("*.*", searchOption);
return Compress(files, lpSourceFolder, lpDestFolder, zipFileName, deleteTempFile);
}

/// <summary>
/// Compress
/// </summary>
/// <param name="files">Array of FileInfo objects to be included in the zip file</param>
/// <param name="lpBaseFolder">Base folder to use when creating relative paths for the files
/// stored in the zip file. For example, if lpBaseFolder is 'C:\zipTest\Files\', and there is a file
/// 'C:\zipTest\Files\folder1\sample.txt' in the 'files' array, the relative path for sample.txt
/// will be 'folder1/sample.txt'</param>
/// <param name="lpDestFolder">Folder to write the zip file into</param>
/// <param name="zipFileName">Name of the zip file to write</param>
public static GZipResult Compress(FileInfo[] files, string lpBaseFolder, string lpDestFolder, stringzipFileName)
{
return Compress(files, lpBaseFolder, lpDestFolder, zipFileName, true);
}

/// <summary>
/// Compress
/// </summary>
/// <param name="files">Array of FileInfo objects to be included in the zip file</param>
/// <param name="lpBaseFolder">Base folder to use when creating relative paths for the files
/// stored in the zip file. For example, if lpBaseFolder is 'C:\zipTest\Files\', and there is a file
/// 'C:\zipTest\Files\folder1\sample.txt' in the 'files' array, the relative path for sample.txt
/// will be 'folder1/sample.txt'</param>
/// <param name="lpDestFolder">Folder to write the zip file into</param>
/// <param name="zipFileName">Name of the zip file to write</param>
/// <param name="deleteTempFile">Boolean, true deleted the intermediate temp file, false leaves the temp file in lpDestFolder (for debugging)</param>
public static GZipResult Compress(FileInfo[] files, string lpBaseFolder, string lpDestFolder, stringzipFileName, bool deleteTempFile)
{
GZipResult result = new GZipResult();

try
{
if (!lpDestFolder.EndsWith("\\"))
{
lpDestFolder += "\\";
}

string lpTempFile = lpDestFolder + zipFileName + ".tmp";
string lpZipFile = lpDestFolder + zipFileName;

result.TempFile = lpTempFile;
result.ZipFile = lpZipFile;

if (files != null && files.Length > 0)
{
CreateTempFile(files, lpBaseFolder, lpTempFile, result);

if (result.FileCount > 0)
{
CreateZipFile(lpTempFile, lpZipFile, result);
}

// delete the temp file
if (deleteTempFile)
{
File.Delete(lpTempFile);
result.TempFileDeleted = true;
}
}
}
catch //(Exception ex4)
{
result.Errors = true;
}
return result;
}

private static void CreateZipFile(string lpSourceFile, string lpZipFile, GZipResult result)
{
byte[] buffer;
int count = 0;
FileStream fsOut = null;
FileStream fsIn = null;
GZipStream gzip = null;

// compress the file into the zip file
try
{
fsOut = new FileStream(lpZipFile, FileMode.Create, FileAccess.Write, FileShare.None);
gzip = new GZipStream(fsOut, CompressionMode.Compress, true);

fsIn = new FileStream(lpSourceFile, FileMode.Open, FileAccess.Read, FileShare.Read);
buffer = new byte[fsIn.Length];
count = fsIn.Read(buffer, 0, buffer.Length);
fsIn.Close();
fsIn = null;

// compress to the zip file
gzip.Write(buffer, 0, buffer.Length);

result.ZipFileSize = fsOut.Length;
result.CompressionPercent = GetCompressionPercent(result.TempFileSize, result.ZipFileSize);
}
catch //(Exception ex1)
{
result.Errors = true;
}
finally
{
if (gzip != null)
{
gzip.Close();
gzip = null;
}
if (fsOut != null)
{
fsOut.Close();
fsOut = null;
}
if (fsIn != null)
{
fsIn.Close();
fsIn = null;
}
}
}

private static void CreateTempFile(FileInfo[] files, string lpBaseFolder, string lpTempFile, GZipResult result)
{
byte[] buffer;
int count = 0;
byte[] header;
string fileHeader = null;
string fileModDate = null;
string lpFolder = null;
int fileIndex = 0;
string lpSourceFile = null;
string vpSourceFile = null;
GZipFileInfo gzf = null;
FileStream fsOut = null;
FileStream fsIn = null;

if (files != null && files.Length > 0)
{
try
{
result.Files = new GZipFileInfo[files.Length];

// open the temp file for writing
fsOut = new FileStream(lpTempFile, FileMode.Create, FileAccess.Write, FileShare.None);

foreach (FileInfo fi in files)
{
lpFolder = fi.DirectoryName + "\\";
try
{
gzf = new GZipFileInfo();
gzf.Index = fileIndex;

// read the source file, get its virtual path within the source folder
lpSourceFile = fi.FullName;
gzf.LocalPath = lpSourceFile;
vpSourceFile = lpSourceFile.Replace(lpBaseFolder, string.Empty);
vpSourceFile = vpSourceFile.Replace("\\", "/");
gzf.RelativePath = vpSourceFile;

fsIn = new FileStream(lpSourceFile, FileMode.Open, FileAccess.Read, FileShare.Read);
buffer = new byte[fsIn.Length];
count = fsIn.Read(buffer, 0, buffer.Length);
fsIn.Close();
fsIn = null;

fileModDate = fi.LastWriteTimeUtc.ToString();
gzf.ModifiedDate = fi.LastWriteTimeUtc;
gzf.Length = buffer.Length;

fileHeader = fileIndex.ToString() + "," + vpSourceFile + "," + fileModDate + "," + buffer.Length.ToString() + "\n";
header = Encoding.Default.GetBytes(fileHeader);

fsOut.Write(header, 0, header.Length);
fsOut.Write(buffer, 0, buffer.Length);
fsOut.WriteByte(10); // linefeed

gzf.AddedToTempFile = true;

// update the result object
result.Files[fileIndex] = gzf;

// increment the fileIndex
fileIndex++;
}
catch //(Exception ex1)
{
result.Errors = true;
}
finally
{
if (fsIn != null)
{
fsIn.Close();
fsIn = null;
}
}
if (fsOut != null)
{
result.TempFileSize = fsOut.Length;
}
}
}
catch //(Exception ex2)
{
result.Errors = true;
}
finally
{
if (fsOut != null)
{
fsOut.Close();
fsOut = null;
}
}
}

result.FileCount = fileIndex;
}

public static GZipResult Decompress(string lpSourceFolder, string lpDestFolder, string zipFileName)
{
return Decompress(lpSourceFolder, lpDestFolder, zipFileName, true, true, null, null, 4096);
}

public static GZipResult Decompress(string lpSourceFolder, string lpDestFolder, string zipFileName, boolwriteFiles, string addExtension)
{
return Decompress(lpSourceFolder, lpDestFolder, zipFileName, true, writeFiles, addExtension, null, 4096);
}

public static GZipResult Decompress(string lpSrcFolder, string lpDestFolder, string zipFileName,
bool deleteTempFile, bool writeFiles, string addExtension, Hashtable htFiles, int bufferSize)
{
GZipResult result = new GZipResult();

if (!lpDestFolder.EndsWith("\\"))
{
lpDestFolder += "\\";
}

string lpTempFile = lpSrcFolder + zipFileName + ".tmp";
string lpZipFile = lpSrcFolder + zipFileName;

result.TempFile = lpTempFile;
result.ZipFile = lpZipFile;

string line = null;
string lpFilePath = null;
string lpFolder = null;
GZipFileInfo gzf = null;
FileStream fsTemp = null;
ArrayList gzfs = new ArrayList();
bool write = false;

if (string.IsNullOrEmpty(addExtension))
{
addExtension = string.Empty;
}
else if (!addExtension.StartsWith("."))
{
addExtension = "." + addExtension;
}

// extract the files from the temp file
try
{
fsTemp = UnzipToTempFile(lpZipFile, lpTempFile, result);
if (fsTemp != null)
{
while (fsTemp.Position != fsTemp.Length)
{
line = null;
while (string.IsNullOrEmpty(line) && fsTemp.Position != fsTemp.Length)
{
line = ReadLine(fsTemp);
}

if (!string.IsNullOrEmpty(line))
{
gzf = new GZipFileInfo();
if (gzf.ParseFileInfo(line) && gzf.Length > 0)
{
gzfs.Add(gzf);
lpFilePath = lpDestFolder + gzf.RelativePath;
lpFolder = GetFolder(lpFilePath);
gzf.LocalPath = lpFilePath;

write = false;
if (htFiles == null || htFiles.ContainsKey(gzf.RelativePath))
{
gzf.RestoreRequested = true;
write = writeFiles;
}

if (write)
{
// make sure the folder exists
if (!Directory.Exists(lpFolder))
{
Directory.CreateDirectory(lpFolder);
}

// read from fsTemp and write out the file
gzf.Restored = WriteFile(fsTemp, gzf.Length, lpFilePath + addExtension, bufferSize);
}
else
{
// need to advance fsTemp
fsTemp.Position += gzf.Length;
}
}
}
}
}
}
catch //(Exception ex3)
{
result.Errors = true;
}
finally
{
if (fsTemp != null)
{
fsTemp.Close();
fsTemp = null;
}
}

// delete the temp file
try
{
if (deleteTempFile)
{
File.Delete(lpTempFile);
result.TempFileDeleted = true;
}
}
catch //(Exception ex4)
{
result.Errors = true;
}

result.FileCount = gzfs.Count;
result.Files = new GZipFileInfo[gzfs.Count];
gzfs.CopyTo(result.Files);
return result;
}

private static string ReadLine(FileStream fs)
{
string line = string.Empty;

const int bufferSize = 4096;
byte[] buffer = new byte[bufferSize];
byte b = 0;
byte lf = 10;
int i = 0;

while (b != lf)
{
b = (byte)fs.ReadByte();
buffer[i] = b;
i++;
}

line = System.Text.Encoding.Default.GetString(buffer, 0, i - 1);

return line;
}

private static bool WriteFile(FileStream fs, int fileLength, string lpFile, int bufferSize)
{
bool success = false;
FileStream fsFile = null;

if (bufferSize == 0 || fileLength < bufferSize)
{
bufferSize = fileLength;
}

int count = 0;
int remaining = fileLength;
int readSize = 0;

try
{
byte[] buffer = new byte[bufferSize];
fsFile = new FileStream(lpFile, FileMode.Create, FileAccess.Write, FileShare.None);

while (remaining > 0)
{
if (remaining > bufferSize)
{
readSize = bufferSize;
}
else
{
readSize = remaining;
}

count = fs.Read(buffer, 0, readSize);
remaining -= count;

if (count == 0)
{
break;
}

fsFile.Write(buffer, 0, count);
fsFile.Flush();

}
fsFile.Flush();
fsFile.Close();
fsFile = null;

success = true;
}
catch //(Exception ex2)
{
success = false;
}
finally
{
if (fsFile != null)
{
fsFile.Flush();
fsFile.Close();
fsFile = null;
}
}
return success;
}

private static string GetFolder(string lpFilePath)
{
string lpFolder = lpFilePath;
int index = lpFolder.LastIndexOf("\\");
if (index != -1)
{
lpFolder = lpFolder.Substring(0, index + 1);
}
return lpFolder;
}
private static FileStream UnzipToTempFile(string lpZipFile, string lpTempFile, GZipResult result)
{
FileStream fsIn = null;
GZipStream gzip = null;
FileStream fsOut = null;
FileStream fsTemp = null;

const int bufferSize = 4096;
byte[] buffer = new byte[bufferSize];
int count = 0;

try
{
fsIn = new FileStream(lpZipFile, FileMode.Open, FileAccess.Read, FileShare.Read);
result.ZipFileSize = fsIn.Length;

fsOut = new FileStream(lpTempFile, FileMode.Create, FileAccess.Write, FileShare.None);
gzip = new GZipStream(fsIn, CompressionMode.Decompress, true);
while (true)
{
count = gzip.Read(buffer, 0, bufferSize);
if (count != 0)
{
fsOut.Write(buffer, 0, count);
}
if (count != bufferSize)
{
break;
}
}
}
catch //(Exception ex1)
{
result.Errors = true;
}
finally
{
if (gzip != null)
{
gzip.Close();
gzip = null;
}
if (fsOut != null)
{
fsOut.Close();
fsOut = null;
}
if (fsIn != null)
{
fsIn.Close();
fsIn = null;
}
}

fsTemp = new FileStream(lpTempFile, FileMode.Open, FileAccess.Read, FileShare.None);
if (fsTemp != null)
{
result.TempFileSize = fsTemp.Length;
}
return fsTemp;
}

private static int GetCompressionPercent(long tempLen, long zipLen)
{
double tmp = (double)tempLen;
double zip = (double)zipLen;
double hundred = 100;

double ratio = (tmp - zip) / tmp;
double pcnt = ratio * hundred;

return (int)pcnt;
}
}

压缩解压缩的操作如下：

//Compress三个参数分别是“要压缩的目标目录”，“保存压缩文件的目录”，压缩文件名
GZip.Compress(@"E:\much\", @"E:\much\", "ziptest");

//Decompress三个参数分别是"压缩包所在目录","要解压到的目录",“压缩包名”
//如果压缩包所在目录不存在则解压不会成功
GZip.Decompress(@"E:\much\zip\", @"E:\much\zip\", "ziptest");