C++：自定义对象序列化/反序列化失败

Question

我在从存储文件读取序列化对象时遇到问题。 （请参阅下面的代码）。

序列化过程“有效”（虽然可能写得很差），并且因为无法知道用户是否传递了std :: ios :: binary标志或者没有选择不使用格式化用whitespace输出。 （这也节省内存为大量像素数据的潜在对我并没有失去。）

我第一次尝试看起来一样的样品，但int小号是unsigned char s的意图位压缩的下半部分和上半部分放入char s中，然后重新组装它们。

目前我可以读取所有的数据到一个文件中，但是当我试图读取第一片非校验和数据，要么返回0（与char S中的尝试的情况下）或垃圾的（在的情况下与int S上的尝试）

连载：

std::ostream& operator<<(std::ostream& os, const Sprite& data) { 
    int dF = data._dimensions.first; 
    int dS = data._dimensions.second; 

    int cF = data._center.first; 
    int cS = data._center.second; 

    int fF = data._frameDimensions.first; 
    int fS = data._frameDimensions.second; 

    double sF = data._scaleDimensions.first; 
    double sS = data._scaleDimensions.second; 


    std::string name(*data._file); 
    name.shrink_to_fit(); 
    os << 'S' << 'P' << 'R' << (name.length() + 1) << name.c_str() << dF << dS << cF << cS << fF << fS << sF << sS; 
    for(int x = 0; x < data._dimensions.first; ++x) { 
     for(int y = 0; y < data._dimensions.second; ++y) { 
      int color = getpixel(data._image, x, y); 
      os << static_cast<unsigned char>(getr(color)) << static_cast<unsigned char>(getg(color)) << static_cast<unsigned char>(getb(color)); 
     } 
    } 
    int tint = data._tint; 
    os << static_cast<unsigned char>(getr(tint)) << static_cast<unsigned char>(getg(tint)) << static_cast<unsigned char>(getb(tint)); 
    os << data._tintIntensity << data._alpha; 
    return os; 
} 

反序列化：

std::istream& operator>>(std::istream& is, Sprite& data) { 
    char checksum[3]; 
    is >> checksum[0] >> checksum[1] >> checksum[2]; 
    if(checksum[0] != 'S' || checksum[1] != 'P' || checksum[2] != 'R') { 
     is.setstate(std::ios::failbit); 
     return is; 
    } 
    int name_length; 
    is >> name_length; 

    std::string name(name_length, '\0'); 

    for(int i = 0; i <= name_length; ++i) { 
     char current_char = '\0'; 
     is >> current_char; 
     name[i] = current_char; 
    } 

    int upper = 0; 
    int lower = 0; 
    is >> upper; 
    is >> lower; 
    data._dimensions.first = (upper << 8) | lower; 

    upper = 0; 
    lower = 0; 
    is >> upper >> lower; 
    data._dimensions.second = ((upper << 8) | lower); 

    upper = 0; 
    lower = 0; 
    is >> upper >> lower; 
    data._center.first = ((upper << 8) | lower); 

    upper = 0; 
    lower = 0; 
    is >> upper >> lower; 
    data._center.second = ((upper << 8) | lower); 

    upper = 0; 
    lower = 0; 
    is >> upper >> lower; 
    data._frameDimensions.first = ((upper << 8) | lower); 

    upper = 0; 
    lower = 0; 
    is >> upper >> lower; 
    data._frameDimensions.second = ((upper << 8) | lower); 

    double f = 0.0; 
    double s = 0.0; 
    is >> f >> s; 
    data._scaleDimensions.first = f; 
    data._scaleDimensions.second = s; 

    destroy_bitmap(data._image); 
    data._image = NULL; 
    data._image = create_bitmap(data._dimensions.first, data._dimensions.second); 
    for(int x = 0; x < data._dimensions.first; ++x) { 
     for(int y = 0; y < data._dimensions.second; ++y) { 
      unsigned char r = 0; 
      unsigned char g = 0; 
      unsigned char b = 0; 
      is >> r >> g >> b; 
      int color = ((r << 16) | (g << 8) | b); //0xRRGGBB 
      putpixel(data._image, x, y, color); 
     } 
    } 
    unsigned char rtint = 0; 
    unsigned char gtint = 0; 
    unsigned char btint = 0; 
    is >> rtint >> gtint >> btint; 
    data._tint = ((rtint << 16) | (gtint << 8) | btint); //0xRRGGBB 

    is >> data._tintIntensity; 
    is >> data._alpha; 
    return is; 
} 

Answer 1

不应deserial化是这样的：

int upper = 0; 
int lower = 0; 
is >> upper; 
is >> lower; 
data._dimensions.first = upper; 
data._dimensions.second = lower; 

和中心相似，frameDimensions

Answer 2

我会用bitfileds。之后请不要忘记添加#pragma pack(1)和#pragma pack()。由于计算机只能处理字节，因此必须确保您的位域是8的倍数。此外，位的打包依赖于编译器/机器，所以您的阅读器应该使用相同的编译器进行编译。 然后只是使用例如：

somefilestream.write(&some_bitfield_struct, sizeof(some_bitfield_struct));