UFT8和UCS2互轉效API使用進行拆分字數如圖

/*
 *	函式：
 *		 utf8_to_ucs2（utf8轉ucs2）
 *  引數：
 *		utf8：utf8資料
 *		utf8_lenght：utf8資料長度
 *		ucs2：儲存ucs2資料空間
 *		ucs2_lenght：儲存ucs2資料空間長度
 *  返回值：
 *		返回轉換後的ucs2位元組長度
 *	 備註：
 *		ucs2等於NULL或utf8_lenght小於0都會作為統計不做賦值操作
 * ssdwujianhua 2018/04/26 
 */
unsigned int utf8_to_ucs2(const char * utf8, unsigned int utf8_lenght, char *ucs2, unsigned int ucs2_lenght)
{
	if ( utf8_lenght < 1 && utf8_lenght > ucs2_lenght)
	{
		return 0;
	}
	unsigned int utf8_pos = 0;	   //位元組偏移位置
	unsigned int ucs2_pos = 0;
	bool bcount = true; //是否統計
	if(ucs2 != NULL || ucs2_lenght < 0)
	{
		bcount = false;
	}
	while(true)
	{
		if((utf8[utf8_pos]&0x80)==0) //1位元組
		{
			if( !bcount )
			{
				ucs2[ucs2_pos]=0;  
				ucs2[ucs2_pos+1]=utf8[utf8_pos]&0x7f; 
			}
			utf8_pos+=1;
			ucs2_pos+=2;
		}
		else if((utf8[utf8_pos]&0xe0)==0xc0)//2位元組
		{
			if(!bcount)
			{
				ucs2[ucs2_pos]=(utf8[utf8_pos]&0x1f)>>2;  
				ucs2[ucs2_pos+1]=((utf8[utf8_pos]&0x03)<<6)|(utf8[utf8_pos+1]&0x3f);
			}
			utf8_pos+=2;
			ucs2_pos+=2;
		}
		else if((utf8[utf8_pos]&0xf0)==0xe0)//3位元組
		{
			if(!bcount)
			{
				ucs2[ucs2_pos]=((utf8[utf8_pos]&0x0f)<<4)|((utf8[utf8_pos+1]&0x3f)>>2);  
				ucs2[ucs2_pos+1]=((utf8[utf8_pos+1]&0x03)<<6)|(utf8[utf8_pos+2]&0x3f); 
			}
			utf8_pos+=3;
			ucs2_pos+=2;
		}
		else
		{
			return -1;
		}

		if ( utf8_pos >= utf8_lenght)
		{
			if(!bcount)
				ucs2[ucs2_pos]='\0';
			break;
		}
	}
	return ucs2_pos;
}

 /*
  *	函式：
  *		 ucs2_to_utf8
  *  引數：
  *		ucs2：ucs2資料
  *		ucs2_lenght：ucs2資料長度
  *		utf8：儲存utf8資料空間
  *		utf8_lenght：儲存utf8資料空間長度
  *  返回值：
  *		返回轉換後的utf8位元組長度
  *	 備註：
  *		uft8等於NULL或utf8_lenght小於0都會作為統計不做賦值操作
  * ssdwujianhua 2018/04/26 
  */
unsigned int ucs2_to_utf8(const char *ucs2, unsigned int ucs2_lenght, char * utf8, unsigned int utf8_lenght)
{
	if ( utf8_lenght < 1 && (utf8_lenght > ucs2_lenght))
	{
		return 0;
	}
	unsigned int utf8_pos = 0;	   //位元組偏移位置
	unsigned int ucs2_pos = 0;
	bool bcount = true; //是否統計
	if(utf8 != NULL || utf8_lenght < 0)
	{
		bcount = false;
	}
	while(true)
	{
		if (ucs2[ucs2_pos] == 0x00 && ucs2[ucs2_pos+1] <= 0x7f) //2個位元組轉成一個位元組
		{
			if(!bcount)
			{
				utf8[utf8_pos]=ucs2[ucs2_pos+1]&0x7f;
			}
			ucs2_pos+=2;
			utf8_pos+=1;
		}
		else if ((ucs2[ucs2_pos]&0xf8)==0)//兩個位元組處理
		{
			if(!bcount)
			{
				utf8[utf8_pos]=0xc0|((ucs2[ucs2_pos]&0x07)<<2)|((ucs2[ucs2_pos+1]&0xc0)>>6);   
				utf8[utf8_pos+1]=0x80|ucs2[ucs2_pos+1]&0x3f;
			}
			ucs2_pos+=2;
			utf8_pos+=2;
		}
		else//三個位元組處理
		{
			if(!bcount)
			{
				utf8[utf8_pos]=0xe0|((ucs2[ucs2_pos]&0xf0)>>4);  
				utf8[utf8_pos+1]=0x80|((ucs2[ucs2_pos]&0x0f)<<2)|((ucs2[ucs2_pos+1]&0xc0)>>6);
				utf8[utf8_pos+2]=0x80|ucs2[ucs2_pos+1]&0x3f;
			}
			ucs2_pos+=2;
			utf8_pos+=3;
		}

		if (ucs2_pos >= ucs2_lenght )
		{
			if(!bcount)
				utf8[utf8_pos] = '\0';
			break;
		}
	}
	return utf8_pos;
}