c++ - 读取 .bmp 文件 C++，错误的值？

Question

这是我从 bmp 文件中读取的代码(使用 windows.h)。它从 BITMAPFILEHEADER 读取正确的值，但从 BITMAPINFOHEADER 读取的所有值都是 40(十六进制的 28)。怎么了？

ifstream file("d3.bmp",ios::binary);
BITMAPFILEHEADER fheader;
BITMAPINFOHEADER aImg;

ofstream fileOut("newfile5.txt",ios::app);

file.read((char*)&fheader.bfType, sizeof(WORD));
fileOut<<std::hex<<fheader.bfType<<"\n";
file.read((char*)&fheader.bfSize, sizeof(DWORD));
fileOut<<fheader.bfSize<<"\n";
file.read((char*)&fheader.bfReserved1, sizeof(WORD));
fileOut<<fheader.bfReserved1<<"\n";
file.read((char*)&fheader.bfReserved2, sizeof(WORD));
fileOut<<fheader.bfReserved2<<"\n";
file.read((char*)&fheader.bfOffBits, sizeof(DWORD));
fileOut<<fheader.bfOffBits<<"\n";


file.read((char*)&aImg.biSize,sizeof(DWORD));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biWidth, sizeof(LONG));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biHeight, sizeof(LONG));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biPlanes, sizeof(WORD));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biBitCount, sizeof(WORD));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biCompression, sizeof(DWORD));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biSizeImage, sizeof(DWORD));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biXPelsPerMeter, sizeof(LONG));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biYPelsPerMeter, sizeof(LONG));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biClrUsed, sizeof(DWORD));
fileOut<<aImg.biSize<<"\n";
file.read((char*)&aImg.biClrImportant, sizeof(DWORD));
fileOut<<aImg.biSize<<"\n";

Answer 1

我打赌读取的值是正确的，只是你总是输出同一个字节一遍又一遍:

file.read((char*)&aImg.biSize,sizeof(DWORD));
fileOut<<aImg.biSize<<"\n"; //ok, biSize
file.read((char*)&aImg.biWidth, sizeof(LONG));
fileOut<<aImg.biSize<<"\n"; //wait, biSize again?
file.read((char*)&aImg.biHeight, sizeof(LONG));
fileOut<<aImg.biSize<<"\n"; //well somehow I'm getting suspicious
file.read((char*)&aImg.biPlanes, sizeof(WORD));
fileOut<<aImg.biSize<<"\n"; //...
file.read((char*)&aImg.biBitCount, sizeof(WORD));
...