1 void CGetFileSizeDlg::OnBnClickedButton1()
 2 {
 3     CString strFile;
 4     GetDlgItemText(IDC_EDIT1, strFile);
 5     DWORD dwHigh = 0;//(文件大小超过4GB)存放33-64位高位
 6     DWORD dwLow = 0;//存放1-32位低位
 7     HANDLE hFile = CreateFile(strFile, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
 8     if (hFile == INVALID_HANDLE_VALUE) {
 9         DWORD errCode = GetLastError();
10         CString szErr;
11         szErr.Format(_T("CreateFile出错啦!错误代码是%d"), errCode);
12         MessageBox(szErr);
13         CloseHandle(hFile);
14         return;
15     }
16     dwLow = GetFileSize(hFile, &dwHigh);
17     LONGLONG lTotal = ((LONGLONG)dwHigh << 32) | dwLow;//形成最终8字节的文件大小LONGLONG(INT64)型数
18     DOUBLE dbTotal = (DOUBLE)lTotal;
19     DOUBLE kbSize = dbTotal / 1024;
20     DOUBLE mbSize = dbTotal / (1024*1024);
21     DOUBLE gbSize = dbTotal / (1024*1024*1024);
22     CString cbSize;
23     cbSize.Format(_T("文件大小是%lld字节(%0.2fKB,%0.2fMB,%0.2fGB)"), lTotal,kbSize,mbSize,gbSize);
24     MessageBox(cbSize);
25     CloseHandle(hFile);
26     return;
27 }