编码UTF8,UCS...

最近学习了下编码

以下地址可以很好的学习到相关的知识

http://dev.youkuaiyun.com/develop/article/69/69883.shtm

http://dev.youkuaiyun.com/develop/article/72/72888.shtm

其中讲了UTF8的编码

当要表示的内容是　7位　的时候就用一个字节：0******* 　第一个0为标志位，剩下的空间正好可以表示ASCII　0－127　的内容。
　　当要表示的内容在　8　到　11　位的时候就用两个字节：110***** 10****** 　第一个字节的110和第二个字节的10为标志位。
　　当要表示的内容在　12　到　16　位的时候就用三个字节：1110***** 10****** 10****** 　　　和上面一样，第一个字节的1110和第二、三个字节的10都是标志位，剩下的空间正好可以表示汉字。
　　以此类推：
四个字节：11110**** 10****** 10****** 10******
　　五个字节：111110*** 10****** 10****** 10****** 10******
　　六个字节：1111110** 10****** 10****** 10****** 10****** 10******
　　.............................................

我自己写了转换的代码如下

UCS和UTF8相互转换

int UCS2UTF8(wchar_t* pUCS,unsigned char* pUTF8)
{
 int UCSlen = 0, UTF8len = 0, i;
 unsigned char* pTempUTF8 = NULL;
 UCSlen = wcslen(pUCS);

 if(pUCS == NULL || pUTF8 == NULL)
  return -1;
 
 pTempUTF8 = pUTF8;
 for(i = 0; i < UCSlen; i++)
 {
  if(pUCS[i] <= 0x007F)//1 byte 0xxxxxxx
  {
   *(pTempUTF8++) = LOBYTE(pUCS[i]);
   UTF8len++;
  }
  else if(pUCS[i] <=0x07FF)//2 bytes 110xxxxx 10xxxxxx
  {
   *(pTempUTF8++) = HIBYTE(pUCS[i] << 2) & 0x3F | 0xC0;
   *(pTempUTF8++) = LOBYTE(pUCS[i] & 0x3f) | 0x80;
   UTF8len += 2;
  }
  else//3 bytes 1110xxxx 10xxxxxx 10xxxxxx
  {
   *(pTempUTF8++) = HIBYTE(pUCS[i] >> 4) | 0xe0;
   *(pTempUTF8++) = HIBYTE(pUCS[i] << 2) & 0x3F | 0x80;
   *(pTempUTF8++) = LOBYTE(pUCS[i]) & 0x3F | 0x80;
   UTF8len += 3;
  }
 }
 
 return UTF8len;
}
int UTF82UCS(unsigned char *pUTF8, wchar_t *pUCS)
{
 int UCSlen = 0, i;
 unsigned char *pTempUCS = NULL;
 unsigned char *pTempUTF8 = NULL;

 if(pUCS == NULL || pUTF8 == NULL)
  return -1;
 UCSlen = MultiByteToWideChar(CP_UTF8,0,pUTF8,-1,NULL,0);
 UCSlen--;
 pTempUCS = (char*)pUCS;
 pTempUTF8 = pUTF8;
 for(i = 0; i < UCSlen; i++)
 {
  if((*pTempUTF8) <= 0x7F)  //1 byte
  {
   *(pTempUCS + 1) = 0x00;
   *pTempUCS = *(pTempUTF8++);
   pTempUCS += 2;
  }
  else if((*pTempUTF8) >= 0xC0 && (*pTempUTF8) <= 0xDF)//2 bytes
  {
   *(pTempUCS + 1) = ((*pTempUTF8) >> 2) & 0x07;
   *pTempUCS = ((*pTempUTF8) << 6) | (*(pTempUTF8 + 1) & 0x3F);
   pTempUTF8 += 2;
   pTempUCS += 2;
  }
  else//3 bytes
  {
   *(pTempUCS + 1) = ((*pTempUTF8) << 4) | ((*(pTempUTF8 + 1) >> 2) & 0x0F);
   pTempUTF8++;
   *pTempUCS = ((*pTempUTF8) << 6) | (*(pTempUTF8+1) & 0x3F);
   pTempUTF8 += 2;
   pTempUCS += 2;
  }
 }
 return UCSlen;
}

其他编码和UCS转换

int ToUCS(unsigned char *p,wchar_t* pUCS,int codepage)
{
 int len = 0;

 if(pUCS == NULL || p == NULL)
  return -1;
 len = MultiByteToWideChar(codepage,0,p,-1,NULL,0);
 MultiByteToWideChar(codepage,0,p,-1,pUCS,len);
 return len;
}

int UCSTo(wchar_t* pUCS,char *p,int codepage)
{
 int len = 0;
 
 if(pUCS == NULL || pBIG5 == NULL)
  return -1;

 len = WideCharToMultiByte(codepage,0,pUCS,-1,NULL,0,NULL,NULL);
 WideCharToMultiByte(codepage,0,pUCS,-1,p,len,NULL,NULL);
 len--;
 return len;
}

这里的codepage在MSDN定义如下

Bit	Code page	Description
ANSI
0	1252	Latin 1
1	1250	Latin 2: Eastern Europe
2	1251	Cyrillic
3	1253	Greek
4	1254	Turkish
5	1255	Hebrew
6	1256	Arabic
7	1257	Baltic
8	1258	VietNam
9 - 15		Reserved for ANSI
ANSI and OEM
16	874	Thai
17	932	Japanese, Shift-JIS
18	936	Chinese: Simplified chars—PRC and Singapore
19	949	Korean Unified Hangeul Code (Hangeul TongHabHyung Code)
20	950	Chinese: Traditional chars—Hong Kong SAR, PRC and Taiwan
21	1361	Korean (Johab)
22 - 29		Reserved for alternate ANSI and OEM
30 - 31		Reserved by system.
OEM
32 - 46		Reserved for OEM
47	1258	VietNam
48	869	IBM Greek
49	866	MS-DOS Russian
50	865	MS-DOS Nordic
51	864	Arabic
52	863	MS-DOS Canadian French
53	862	Hebrew
54	861	MS-DOS Icelandic
55	860	MS-DOS Portuguese
56	857	IBM Turkish
57	855	IBM Cyrillic; primarily Russian
58	852	Latin 2
59	775	Baltic
60	737	Greek; former 437 G
61	708	Arabic; ASMO 708
62	850	Western European/Latin 1
63	437	US