如何在Swift中使用sizeThatFits？

我有一个文本视图和这样的视图

let lb = UITextView() let view = UIView() background_img_view.addSubview(about_txt) 

lb没有固定的高度，它可以是30或300px，我如何使用sizeThatFits使background_img_view的高度取决于lb的？

Answer 1

尝试这个：

 // Get the width you want to fit let fixedWidth = textView.frame.size.width // Calculate the biggest size that fixes in the given CGSize let newSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat.greatestFiniteMagnitude)) // Set the textView's size to be whatever is bigger: The fitted width or the fixedWidth textView.frame.size = CGSize(width: max(newSize.width, fixedWidth), height: newSize.height) // Make the "background_img_view" height match the textView's height background_img_view.frame.size.height = textView.frame.size.height