将按钮的字体大小设置为最大以适合宽度和高度

Question

I'm creating an app for iOS using Xcode and Swift.

I have a button, that fills the screen in width and has a height proportional to the root view. I want the text of the button to be as big as possible while still fitting both in width and in height. I tried setting a really big font size(100), lines to 1 and adjustsFontSizeToFitWidth to true. The effect was, that it makes the font size to fill width and if the text doesn't fit any more (as it is the case in portrait mode on my tablet) it replaces part of the text with "..."

Also in Landscape mode, while most of the text fits perfectly in height, the slash is bigger than the height and is partly outside the button (at the bottom).

Answer 1

the best practice is to place label beneath button. and make button transparent to fill all your label. - do this with right constraints. i wrote small video how to achive that -

https://www.screencast.com/t/u8gb4f5YaBd

Answer 2

You have to use a transparent button and add a label behind that button. There is no other way then hit and try. You have to set the font and check if that is fit to your width or not. Here is some example of recursive function. You have to set label.lineBreakMode = .byCharWrapping and label.numberOflines = 0

func adjustSize() {
     let font = label.font
     label.font = UIFont(name: font!.fontName, size: font!.pointSize + 1)
     let constraintRect = UIScreen.main.bounds.size
     let boundingBox = label.text!.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSAttributedStringKey.font: label.font], context: nil)
     if boundingBox.width < constraintRect.width {
        adjustSize()
     }
}