如何将FontSizeToFitWidth调整为UIButton标签？ ios

Question

when i set adjustsFontSizeToFitWidth to the button UILabel, the text go out side of the button frame, I don't know why ?

here is my code:

            shareBtn = UIButton()

            shareBtn.setTitle(IconsConstants.share, forState: UIControlState.Normal)
            shareBtn.titleLabel?.font = UIFont.iconmoonFont(100)
            shareBtn.titleLabel?.adjustsFontSizeToFitWidth = true;
            shareBtn.contentVerticalAlignment = UIControlContentVerticalAlignment.Center
            shareBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignment.Center


            //EdgeInsets

            shareBtn.contentEdgeInsets = UIEdgeInsets.init(top: 10, left: 10, bottom: 10, right: 10)

and here is the result:

Answer 1

for single line set

shareBtn.titleLabel?.adjustsFontSizeToFitWidth = YES;

instead of this

factLabel.adjustsFontSizeToFitWidth = true;

for multiple line us use

actLabel.numberOfLines = 0;
factLabel.lineBreakMode = NSLineBreakByWordWrapping;
CGSize maximumLabelSize = CGSizeMake(factLabel.frame.size.width, CGFLOAT_MAX);
CGSize expectSize = [factLabel sizeThatFits:maximumLabelSize];
factLabel.frame = CGRectMake(factLabel.frame.origin.x, factLabel.frame.origin.y, expectSize.width, expectSize.height);