Question

c / C ++中以下代码的等价物是什么？

ref BITMAPFILEHEADER bmfh = ref buffer[offset]; //Where buffer is a byte[] array

Answer 1

如果您#include <windows.h>已经有BITMAPFILEHEADER struct。

PBITMAPFILEHEADER bmfh_ptr = (PBITMAPFILEHEADER)(buffer + offset);
// where buffer is a char[] array.

Answer 2

可以找到一个24位BMP读写器的操作系统不可知的C ++实现：http://code.google.com/p/bitmap/source/browse/trunk/bitmap_image.hpp

以下是标题和信息块的结构定义：

struct bitmap_file_header
{
   unsigned short type;
   unsigned int   size;
   unsigned short reserved1;
   unsigned short reserved2;
   unsigned int   off_bits;

   unsigned int struct_size()
   {
      return sizeof(type)     +
            sizeof(size)      +
            sizeof(reserved1) +
            sizeof(reserved2) +
            sizeof(off_bits);
   }
};

struct bitmap_information_header
{
   unsigned int   size;
   unsigned int   width;
   unsigned int   height;
   unsigned short planes;
   unsigned short bit_count;
   unsigned int   compression;
   unsigned int   size_image;
   unsigned int   x_pels_per_meter;
   unsigned int   y_pels_per_meter;
   unsigned int   clr_used;
   unsigned int   clr_important;

   unsigned int struct_size()
   {
      return sizeof(size)             +
             sizeof(width)            +
             sizeof(height)           +
             sizeof(planes)           +
             sizeof(bit_count)        +
             sizeof(compression)      +
             sizeof(size_image)       +
             sizeof(x_pels_per_meter) +
             sizeof(y_pels_per_meter) +
             sizeof(clr_used)         +
             sizeof(clr_important);
   }
};

Answer 3

字面翻译：

BITMAPFILEHEADER *bmfh = &(buffer[offset]);

在c ++中可能更自然：

PBITMAPFILEHEADER bmfh = (PBITMAPFILEHEADER)(buffer+offset);

但要注意，要使这两个工作正常，缓冲区最好被定义为字符类型。

请注意，PBITMAPFILEHEADER被定义为BITMAPFILEHEADER *，就像Windows命名一样。

BITMAPFILEHEADER等效于c / c ++？

3 个答案: