动画修改label上的文字

// 方法一

CATransition *animation = [CATransition animation];

    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    animation.type = kCATransitionFade;

    animation.duration = 0.75;

    [self.label.layer addAnimation:animation forKey:@"kCATransitionFade"];

    self.label.text = @"New";

// 方法二

[UIView transitionWithView:self.label

                      duration:0.25f

                       options:UIViewAnimationOptionTransitionCrossDissolve

                    animations:^{

                        self.label.text = @"Well done!";

                    } completion:nil];

// 方法三

[UIView animateWithDuration:1.0

                     animations:^{

                         self.label.alpha = 0.0f;

                         self.label.text = @"newText";

                         self.label.alpha = 1.0f;

                     }];