压缩与解压缩的实现

参考网址：
开源代码：http://www.zlib.net
zlib使用手册：http://www.zlib.net/manual.html
zlib wince版：http://www.tenik.co.jp/~adachi/wince/
在这里，你可以查看基于各种操作系统平台的压缩与解缩代码实现。

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以下是经过测试的 WinCE 及 WinXP 下的代码

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第一步: 首先到www.zlib.net下载个ZLIB,
WinXP: 解压缩后打开zlib-1.2.3/projects/visualc6/zlib.dsw,选择Win32 LIB Release 按F7编绎生成zlib.lib, zlib.dll.
WinCE: 下载一个for Windows CE 版的包,里面针对各种平台(ARM4, ARM4I, MIPS, X86)有对应的zlibce.dll zlibce.lib.

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第二步: 建立EVC 或者 VC6 的对话框工程.
在工程中添加以下文件:zlib.h, zconf.h, zlib.lib, zlib.dll (或者 zlibce.dll);
这3个文件就在刚才从www.zlib.net下载的软件包中.

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第三步: 包含头文件
#include "zlib.h"
#include "StorageDeal.h"
其中CStorageDeal是我写的文件处理类，功能类似于CFile类。它的类定义如下：
class CStorageDeal : public CStatic
{
// Construction
public:
CStorageDeal();
virtual ~CStorageDeal();

// Attributes
public:
CFile myFile;
DWORD myFileLength;
BOOL FileOpenStaus;

public:
BOOL OpenFile(CString pFileName);
BOOL CloseFile();

DWORD ReadBlockData(BYTE *pData, DWORD blockIndex, DWORD idIndex);
DWORD WriteBlockData(BYTE *pData, DWORD blockIndex, DWORD idIndex);

DWORD GetFileLength();
DWORD SetFileLength(DWORD length);

DWORD ReadData(BYTE *pData, DWORD position, DWORD length);
DWORD WriteData(BYTE *pData, DWORD position, DWORD length);

static BOOL DeleteFile(CString pFileName);
static BOOL RenameFile(CString pOldName, CString pNewName);
};

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第四步: 添加压缩与解压缩代码

压缩代码:
BOOL CMyZip_evcDlg::zip(CString srcFileName, CString dstFileName)
{

#ifdef NO_GZCOMPRESS

MessageBox(_T("NO_GZCOMPRESS -- gz* functions cannot compress"));

return FALSE;

#endif

//打开待压缩的文件

CStorageDeal unzipFile;

unzipFile.OpenFile(srcFileName);

int fileLen = unzipFile.GetFileLength();

//创建压缩文件

gzFile zipFile;

CString zipFileName = srcFileName +_T(".gz");

int zipFileNameLen = zipFileName.GetLength();

#ifdef ARM // WinCE下代码

char nameBuff[100]={0};

WideCharToMultiByte(CP_ACP,0,zipFileName,zipFileNameLen,nameBuff,zipFileNameLen,NULL,NULL);

zipFile = gzopen(nameBuff, "wb");

#else // WinXP下大妈

zipFile = gzopen(zipFileName, "wb");

#endif

z_off_t pos;

//临时变量定义

BYTE buff[10000]={0};

int buffLen;

int BlockSize = sizeof(buff);

int BlockLeft = fileLen%BlockSize;

int BlockNum = fileLen/BlockSize;

if(BlockLeft != 0)

{

BlockNum++;

}

//开始压缩

for(int BlockIndex=0;BlockIndex<BlockNum;BlockIndex++)

{

if(BlockLeft != 0)

{

if(BlockIndex < BlockNum - 1)

buffLen = BlockSize;

else

buffLen = BlockLeft;

}

else

{

buffLen = BlockSize;

}

unzipFile.ReadData(buff,BlockIndex*BlockSize,buffLen);

if (zipFile == NULL)

{

MessageBox(_T("gzopen error/n"));

return FALSE;

}

#ifdef ARM

gzwrite(zipFile,(voidp)buff,buffLen);

#else

gzwrite(zipFile,(voidpc)buff,buffLen);

#endif

}

gzclose(zipFile);

unzipFile.CloseFile();

// dest file name is not processed.

// CFile::Rename(zipFileName,dstFileName);

}

解压缩代码:

BOOL CMyZip_evcDlg::unzip(CString srcFileName, CString dstFileName)

{

//打开待解压的文件

gzFile zipFile;

CString zipFileName = srcFileName;

int zipFileNameLen = zipFileName.GetLength();

#ifdef ARM

char nameBuff[100]={0};

WideCharToMultiByte(CP_ACP,0,zipFileName,zipFileNameLen,nameBuff,zipFileNameLen,NULL,NULL);

zipFile = gzopen(nameBuff, "rb");

#else

zipFile = gzopen(zipFileName, "rb");

#endif

if (zipFile == NULL) {

MessageBox(_T("gzopen error"));

return FALSE;

}

//创建文件

CStorageDeal unzipFile;

dstFileName = srcFileName;

dstFileName.TrimRight(_T(".gz"));

unzipFile.OpenFile(dstFileName);

unzipFile.SetFileLength(0);

//临时变量

BYTE buff[1000]={0};

int buffLen = sizeof(buff);

//开始解压

int len;

int pos = 0;

while(1)

{

len = gzread(zipFile, (voidp)buff,buffLen);

if(len==0) break;

unzipFile.WriteData(buff,pos,len);

pos += len;

}

gzclose(zipFile);

unzipFile.CloseFile();

}

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第五步: 调用压缩与解压缩代码

void CMyZIP_vc6Dlg::OnButton1()

{

zip(_T("d://aa.doc"),_T("aa.doc.gz"));
}

void CMyZIP_vc6Dlg::OnButton2()

{

unzip(_T("d://aa.doc.gz"),_T("aa.doc"));

}

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