设置行间距,自动适应高度

//设置行间距  5.0f

    NSMutableAttributedString * attributedString = [[NSMutableAttributedStringalloc] initWithString:self.tipLab.text];

    NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStylealloc] init];

    [paragraphStyle setLineSpacing:5.0f];

    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [self.tipLab.text length])];

    [self.tipLab setAttributedText:attributedString];

    [self.tipLabsizeToFit];