iOS 控制Label只显示一行半

/**
 控制显示一行半的方法

 @param originalContent 原内容
 @param labelWidth label宽度
 @return 展示的内容
 */
- (NSMutableAttributedString *)getSubContentWithOriginalContent:(NSMutableAttributedString *)originalContent andLabelWidth:(CGFloat)labelWidth{
    
    NSAttributedString *subContent = nil;
    CGFloat maxLength = labelWidth * 1.5;//设置字符串最大长度为一行半
    CGFloat length = 0;
    for(int i = 0; i < [originalContent length]; i++)
    {
        subContent = [originalContent attributedSubstringFromRange:NSMakeRange(i,1)];
        // 计算宽度
        CGSize size = [subContent boundingRectWithSize:CGSizeMake(MAXFLOAT, 0.0) options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingTruncatesLastVisibleLine  context:nil].size;
        
        
        length = length + size.width;
        
        //此处截取maxLength,根据需求设置
        if (length >= maxLength) {
            NSMutableAttributedString *resultString = [[NSMutableAttributedString alloc] initWithAttributedString:[originalContent attributedSubstringFromRange:NSMakeRange(0, i)]];
            NSAttributedString *att = [[NSAttributedString alloc] initWithString:@" ..." attributes:self.attributeStyle];
            [resultString appendAttributedString:att];
            return resultString;
        }
    }
    return originalContent;
}