// int2byte.cpp : 定义控制台应用程序的入口点。
//#include "stdafx.h"
#include <Windows.h>/*
#define MAKEWORD(a, b)	((WORD)(((BYTE)(((DWORD_PTR)(a)) & 0xff)) | ((WORD)((BYTE)(((DWORD_PTR)(b)) & 0xff))) << 8))
#define MAKELONG(a, b)	((LONG)(((WORD)(((DWORD_PTR)(a)) & 0xffff)) | ((DWORD)((WORD)(((DWORD_PTR)(b)) & 0xffff))) << 16))
#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))
*/// ==========================================================
//   Big Endian / Small Endian utility functions
// ==========================================================
BOOL IsSmallEndian()
{DWORD wd = 0x22; if( *((BYTE *)&wd) == 0x22 )  // Small Endianreturn TRUE;elsereturn FALSE;
}void SwapShort(WORD *sp) {BYTE *cp = (BYTE *)sp, t = cp[0]; cp[0] = cp[1]; cp[1] = t;
}void SwapLong(DWORD *lp) {BYTE *cp = (BYTE *)lp, t = cp[0]; cp[0] = cp[3]; cp[3] = t;t = cp[1]; cp[1] = cp[2]; cp[2] = t;
}// int 2 byte
BYTE *Int2Byte(int nVal)
{BYTE *pByte = new BYTE[4];for (int i = 0; i<4;i++){pByte[i] = (BYTE)(nVal >> 8*(3-i) & 0xff);}return pByte;
}// byte 2 int
int Byte2Int(BYTE *pb)
{// assume the length of pb is 4int nValue=0;for(int i=0;i < 4; i++){nValue += ( pb[i] & 0xFF)<<(8*(3-i));}return nValue;
}int _tmain(int argc, _TCHAR* argv[])
{//PC， 小端字节//BYTE *byte = Int2Byte(0x12345678);printf("byte[0]=0x%xh,byte[1]=0x%xh,byte[2]=0x%xh, byte[3]=0x%xh\n", byte[0], byte[1], byte[2],byte[3]);int nVal = Byte2Int(byte);printf("nVal=0x%xh\n\n",nVal);//// 小端字节应该是得到 0xefcdab89, 大端得到0x89abcdefWORD wLow, wHigh;DWORD dwData;BYTE b[4] = {0x89, 0xab, 0xcd, 0xef};DWORD dwVal = 0xefcdab89;// DWORD分解成BYTE数组WORD lo = LOWORD(dwVal),hi = HIWORD(dwVal);printf("lo=0x%xh,hi=0x%xh\n", lo, hi);//BYTE数组组合成DWORDwLow = MAKEWORD(b[0],b[1]);wHigh = MAKEWORD(b[2], b[3]);dwData = MAKELONG(wLow, wHigh);printf("wLow=0x%xh,wHigh=0x%xh,dwData=0x%xh\n", wLow, wHigh, dwData);getchar();return 0;
}