utf8串输出中文

bool Utf8ToZhong(const std::string &utf8_str, std::string *result_str) {
	if(utf8_str.size() == 0) {
		return false;
	}
	int move_flag = 0;
	string str;
	int start = 0,end = utf8_str.size();
	char str_zhong[128];
	int str_it = 0;
	while(start < end) {
		if(utf8_str[start] == '%') {
			if(move_flag == 0) {//汉字起始,计算一个汉字是几个字节
				int y = 0; 
				y = HexChar2Dec(utf8_str[start+1]);
				y = (y<<4) +HexChar2Dec(utf8_str[start+2]);
				int flag = 7; 
				while(flag > 0) { 
					if((y&(1<<flag)) == 0) { 
						break;
					}    
					flag--;
				}    
				move_flag = 7-flag;//总共几个字节
			}    
			start++;
		}    
		else {
			if(move_flag == 0) { 
				str += utf8_str[start];
				start++;
			}    
			else {
				int y = 0; 
				y = HexChar2Dec(utf8_str[start]);
				y = (y<<4) +HexChar2Dec(utf8_str[start+1]);
				str_zhong[str_it] = y; 
				str += str_zhong[str_it];
				str_it++;
				start += 2;//偏移掉一个%
				if(move_flag > 0) {
					move_flag--;  //处理一个字节，消掉一个字节
				}
			}
		}
	}
	*result_str = str;
	return true;
}