C++ 文件流

 1 //读取文件内容
 2 
 3 CString filename1;
 4 filename1.Format(_T("\\PHOTO\\%06ld%06ldCredPhoto.jpg"),  batchno, voucherno);
 5 std::ifstream appFile(filename1.GetBuffer(), std::ios::binary);
 6 if (appFile.good())
 7 {
 8     appFile.seekg(0, std::ios::end);
 9     lenFile = (int)appFile.tellg();
10 
11     countDownloadPacket = 0;
12     appFile.seekg(0, std::ios::beg);
13 
14     if (lenFile % perTransSize == 0)
15     {
16         countPacket = lenFile / perTransSize;
17     }
18     else
19     {
20         countPacket = lenFile / perTransSize + 1;
21     }
22     for (int i = countDownloadPacket + 1; i < countPacket + 1; ++i)
23     {
24         memset(szData, 0, perTransSize + 2);
25 
26         appFile.seekg((i-1) * perTransSize, std::ios::beg);
27         appFile.read((char *)szData, perTransSize);
28         lenData = (int)appFile.gcount();    //实际读取的字符数
29         if (lenData == 0)
30         {
31             break;
32         }
33         
34         //szData为此次读取的数据内容，lenData为长度。
35         
36     }
37 }