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C++ 文件大小格式化 

 1 #include <iostream>
 2 #include <windows.h>
 3 using namespace std;
 4
 1 /*文件大小格式化
 2  *param [in] dwSize   xx.xxB 、xx.xxKb 、xx.xxM
 3  */
 4 
 5 LPCTSTR CFileUtil::FileSizeToFormat(DWORD dwSize)
 6 {
 7     TCHAR* strSize = new TCHAR[20];
 8     ZeroMemory(strSize,sizeof(TCHAR) * 20);
 9 
10     double i = pow((double)2,10);
11 
12     if (dwSize < pow((double)2,10))//dwSize < 1024
13     {
14         _stprintf_s(strSize,20,TEXT("%dB"),dwSize);//文件大小 B
15     }
16     else if (pow((double)2,10) <= dwSize &&  dwSize< pow((double)2,20))// 1024 <= dwSize < 1024*1024
17     {
18         float fSize = (float)(dwSize*100/1024)/100;
19         _stprintf_s(strSize,20,TEXT("%.2fKB"),fSize);
20     }
21     else if (pow((double)2,20) <= dwSize && dwSize < pow((double)2,30))// 1024*1024 <= dwSize < 1024*1024*1024
22     {
23         float fSize = (float)(dwSize/1024*100/1024)/100;
24         _stprintf_s(strSize,20,TEXT("%.2fM"),fSize);//文件大小 M
25     }
26     else if (pow((double)2,30) <= dwSize && dwSize < pow((double)2,40)) // 1024*1024*1024 <= dwSize < 1024*1024*1024*1024
27     {
28         float fSize = (float)(dwSize/1024*100/1024/1024)/100;
29         _stprintf_s(strSize,20,TEXT("%.2fG"),fSize);//文件大小 G 
30     }
31     else
32     {
33         float fSize = (float)(dwSize/1024*100/1024/1024/1024)/100;
34         _stprintf_s(strSize,20,TEXT("%.2fT"),fSize);//文件大小 T
35     }
36     
37     return strSize;
38 }

 

 5 
 6 /*根据文件大小进行格式化
 7 *@[in ]  llBytes    文件的长度(B)
 8 *@[out]  pszSize    缓冲区
 9 *@[in ]  clen       缓冲区长度
10 */
11 
12 BOOL FileSizeToStringA(LONGLONG llBytes, char* pszSize, DWORD cLen)
13 {
14     double bytes = (double)llBytes;
15     DWORD cIter = 0;    
16     char* pszUnits[] = { ("B"), ("KB"), ("MB"), ("GB"), ("TB") };
17     DWORD cUnits = sizeof(pszUnits) / sizeof(pszUnits[0]);
18 
19     // move from bytes to KB, to MB, to GB and so on diving by 1024
20     while(bytes >= 1024 && cIter < (cUnits-1))
21     {
22         bytes /= 1024;
23         cIter++;
24     }
25     _snprintf_s(pszSize, cLen, _TRUNCATE,("%.2f %s"), bytes, pszUnits[cIter]);
26     return TRUE;
27 }
28 
29 int main()
30 {
31     char szText[256];
32     FileSizeToStringA(23156,szText,256);
33 
34     cout << "szText:" << szText << endl;
35 
36     getchar();
37     return 0;
38 }

 

posted @ 2015-03-30 16:51  车臣  阅读(717)  评论(0)  编辑  收藏  举报