LOWORD, HIWORD, LOBYTE, HIBYTE

实际上就是宏函数，作用是取对应数据高/低位的

#define LOWORD(l)           ((WORD)(((DWORD_PTR)(l)) & 0xffff))
#define HIWORD(l)           ((WORD)((((DWORD_PTR)(l)) >> 16) & 0xffff))
#define LOBYTE(w)           ((BYTE)(((DWORD_PTR)(w)) & 0xff))
#define HIBYTE(w)           ((BYTE)((((DWORD_PTR)(w)) >> 8) & 0xff))

LOWORD 取32bits的低16bits

HIWORD 取32bits高16bits

LOBYTE 取16bits低8bits

HIBYTE 取16bits高8bits

 

补充：

typedef unsigned char BYTE;
typedef unsigned short WORD;
typedef unsigned long DWORD;