尝试使用 ifstream.read 将数据导入 vector

Question

试图将文件的一部分读入向量结构。 特别是尝试使用标准库读取 exif 数据。 此代码编译但向量（“缓冲区”）是空的。

已经为此工作了几天。学习C++。对 PHP 更有经验。我知道 - 我可能应该研究一些基础知识而不是这个，但这更有趣。任何帮助将不胜感激。

void File_iterate ( const std::string* Filename  ) {

    std::ifstream infile ( *Filename, std::ios::binary );
    if ( !infile ) { std::cout << "Error: file unavailable\n"; exit(1); }

    infile.seekg( 0xE1, std::ios::beg ); // Seek to the position of the 0xE1 tag
    long CopyFrom = infile.tellg();
 
    unsigned short length;
    infile.read(reinterpret_cast<char*>(&length), sizeof(length) ); // Read the two bytes following the 0xE1 tag to obtain the length of the exifData

    infile.seekg( 0, std::ios::end );
    std::cout << "Length of exifData:  " << length << " bytes.\n";
    std::cout << "Size of file:     " << infile.tellg() << " bytes\n";
    long CopyTo = CopyFrom + length;
    std::cout << "Exif Position: " << CopyFrom << " - " << CopyTo << "\n";
 
    std::vector<uint8_t> buffer;
    buffer.reserve(length);
 
    infile.seekg( 0xE1, std::ios::beg ); // Reset input stream
    infile.read( (char*)buffer.data() , length); // <-- THIS DOES NOT WORK :(
  
    std::cout << "Length of buffer: " << buffer.size() << " bytes\n" ;
 
    infile.close();
 
    for ( int i : buffer ) {
        if ( buffer[i] == 0xE1 ) { std::cout << buffer[i]; }
        if ( buffer[i] == 0x9003 ) { std::cout << buffer[i]; }
    }