iOSUILabel自定义行间距时获取高度

　#import "TTTAttributedLabel.h"

NSString *str = @"UILabel自定义行间距时获取高度,UILabel自定义行间距时获取高度,UILabel自定义行间距时获取高度,UILabel自定义行间距时获取高度,UILabel自定义行间距时获取高度,UILabel自定义行间距时获取高度,UILabel自定义行间距时获取高度.";        //创建tttLabel    TTTAttributedLabel *tttLabel = [[TTTAttributedLabel alloc] initWithFrame:CGRectMake(30, 55, 300, 100)];    tttLabel.lineBreakMode = NSLineBreakByCharWrapping;    tttLabel.lineSpacing = 6;//设置行间距    tttLabel.font = [UIFont systemFontOfSize:12];    tttLabel.numberOfLines = 0; //设置行数为0    [tttLabel setText:str];    tttLabel.textAlignment = NSTextAlignmentLeft;    tttLabel.backgroundColor = [UIColor redColor];    [self.view addSubview:tttLabel];        //获取tttLabel的高度    //先通过NSMutableAttributedString设置和上面tttLabel一样的属性,例如行间距,字体    NSMutableAttributedString *attrString = [[NSMutableAttributedString alloc] initWithString:str];    //自定义str和TTTAttributedLabel一样的行间距    NSMutableParagraphStyle *paragrapStyle = [[NSMutableParagraphStyle alloc] init];    [paragrapStyle setLineSpacing:6];    //设置行间距    [attrString addAttribute:NSParagraphStyleAttributeName value:paragrapStyle range:NSMakeRange(0, str.length)];    //设置字体    [attrString addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:12] range:NSMakeRange(0, str.length)];        //得到自定义行间距的UILabel的高度    CGFloat height = [TTTAttributedLabel sizeThatFitsAttributedString:attrString withConstraints:CGSizeMake(300, MAXFLOAT) limitedToNumberOfLines:0].height;        //重新改变tttLabel的frame高度    CGRect rect = tttLabel.frame;    rect.size.height = height;    tttLabel.frame = rect;