iOS_label高度自适应文字

self.replyInfoLabel = [[UILabel alloc] initWithFrame:CGRectZero];

self.replyInfoLabel.font = [UIFont systemFontOfSize:15];

self.replyInfoLabel.text =  self.reply;

self.replyInfoLabel.numberOfLines = 0;//根据最大行数需求来设置

self.replyInfoLabel.lineBreakMode = NSLineBreakByTruncatingTail;

CGSize size = CGSizeMake(SCREEN_WIDTH-30, 45);//labelsize的最大值

CGRect textFrame = self.replyInfoLabel.frame;

NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:self.replyInfoLabel.font,NSFontAttributeName, nil];

textFrame.size.height = [self.replyInfoLabel.text boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:dict context:nil].size.height;

self.replyInfoLabel.frame = CGRectMake(20, 35, SCREEN_WIDTH-30, textFrame.size.height);

[self.contentView addSubview:self.replyInfoLabel];