获取文件CRC32值VC++实现 选择自 ksaiy 的 Blog
首先在头文件里面申明一下： unsigned long Crc32Table[256];
代码开始：
void CGetCrcDlg::OnGetFileCrc() //打开文件然后在EDIT控件里面直接显示文件校验值；{ HANDLE hFile = {NULL}; DWORD dwSize, bytes_read; CString FileNameStr; MakeTable();//生成码表
//打开对话框 CFileDialog dlg(TRUE, NULL, "", OFN_HIDEREADONLY, "All Files (*.*)|*.*||", this); if(IDOK != dlg.DoModal()) return;
FileNameStr = dlg.GetPathName();
hFile = CreateFile(FileNameStr, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL); dwSize = GetFileSize(hFile, NULL);
CString csData(' ', dwSize); ReadFile(hFile, csData.GetBuffer(dwSize), dwSize, &bytes_read, NULL); CloseHandle(hFile); csData.ReleaseBuffer();
int nCRC = Get_CRC(csData, dwSize); char ch[20]; itoa(nCRC, ch, 16); m_FileCrcValue= ch; m_FileCrcValue.MakeUpper(); UpdateData(FALSE);}
void CGetCrcDlg::MakeTable()//动态生成CRC32的码表{ int i,j; unsigned long crc; for (i = 0; i < 256; i++) { crc = i; for (j = 0; j < 8; j++) { if (crc & 1) crc = (crc >> 1) ^ 0xEDB88320; else crc >>= 1; } Crc32Table[i] = crc; }}
int CGetCrcDlg::Get_CRC(CString &csData, DWORD dwSize)//获取crc32值{ ULONG crc(0xffffffff); int len; unsigned char* buffer; len = dwSize; buffer = (unsigned char*)(LPCTSTR)csData; while(len--) crc = (crc >> 8) ^ Crc32Table[(crc & 0xFF) ^ *buffer++]; return crc^0xffffffff;}
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作者Blog：http://blog.csdn.net/ksaiy/
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[【技术文档】]获取文件CRC32值VC++实现