UILabel - Alternative for Deprecated Method “adjustsLetterSpacingToFitWidth”

First of all, your getter and setter are entirely superfluous as shown; wherever you call getter and/or setter, you could simply get/set adjustsLetterSpacingToFitWidth directly.

As for the question of how to do auto-kerning with NSKernAttributeName, Apple's documentation says: “To turn on auto-kerning in the label, set NSKernAttributeName of the string to [NSNull null]”, i.e., you would do something like:

NSMutableAttributedString *s;
s = [[NSMutableAttributedString alloc] initWithString:my_uilabel.text];
[s addAttribute:NSKernAttributeName
          value:[NSNull null]
          range:NSMakeRange(0, s.length)];
my_uilabel.attributedText = s;

But if you did not want to do automatic adjustment of letter spacing but rather find out whether the text fits in the label or not, you might want to check the various methods in NSString UIKit additions. (This guess of intent is based on the wording in the original question.)

转载：http://www.acnenomor.com/466529p1/uilabel-alternative-for-deprecated-method-adjustsletterspacingtofitwidth