如何平衡自适应字体（UIFontMetrics）与UIView尺寸？

Great question—this is such a common headache when working with dynamic type at the extreme end of the scale! Here are some practical theoretical approaches to balance text readability and layout integrity:

• Cap font growth at a safe maximum
  Your initial thought of setting maximum sizes is spot-on. Instead of just limiting the view's size, use UIFontMetrics to define a hard upper limit for the font itself. This way, even when the user cranks the system text to the largest setting, the font won't scale beyond a size you've pre-tested to fit your layout. It cuts off overgrowth at the source, preventing both truncation and layout breakage.

• Lean into adaptive layout containers
  Ditch fixed frames and rely on auto layout with flexible containers like UIStackView. Set text views to numberOfLines = 0 so they can expand vertically, and pair them with constraints that define a reasonable maximum height (so they don't take over the entire screen). This lets the layout adjust to the text size rather than forcing text into a rigid space.

• Adapt the text itself, not just the font
  For longer strings, consider context-aware truncation alternatives: swap in shorter, semantically equivalent copy when text scales to the largest sizes (e.g., "Notifications" → "Alerts") or use adjustsFontSizeToFitWidth with a sensible minimumScaleFactor to let the font shrink just enough to fit without becoming unreadable. Just be careful not to overdo the scaling—readability should always come first.

• Use constraint priorities and layout breakpoints
  Assign lower priorities to non-critical UI elements (like icons or secondary labels) so they get compressed or hidden first when text needs more space. You can also listen for system text size changes and trigger a layout switch at a certain threshold—for example, shifting from a horizontal row to a vertical stack when the text hits its maximum scaled size. This breakpoint approach ensures the UI stays usable even in edge cases.

内容的提问来源于stack exchange，提问作者JJPark