将 字母 和 汉字 长度按 1:2 比例计算

01	-(NSUInteger) unicodeLengthOfString: (NSString *) text {

02	NSUInteger asciiLength = 0;

03	for (NSUInteger i = 0; i < text.length; i++) {

04	unichar uc = [text characterAtIndex: i];

05	asciiLength += isascii(uc) ? 1 : 2;

06

}

07	NSUInteger unicodeLength = asciiLength / 2;

08	if(asciiLength % 2) {

09	unicodeLength++;

10

}

11	return unicodeLength;

12

}