newLabel.lineBreakMode = NSLineBreakByCharWrapping;
newLabel.text = content;
newLabel.adjustsFontSizeToFitWidth=YES;
newLabel.minimumScaleFactor = 10.0/14.0;
adjustsFontSizeToFitWidth 与 NSLineBreakByCharWrapping 无法共用
原文:https://www.cnblogs.com/willbin/p/10107135.html