为啥 UIView Animation 不会触发 CALayer 的 addAnimation:forKey:？

Posted 2023-03-13

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【中文标题】为啥 UIView Animation 不会触发 CALayer 的 addAnimation:forKey:？【英文标题】：Why UIView Animation doesn't trigger CALayer's addAnimation:forKey:?为什么 UIView Animation 不会触发 CALayer 的 addAnimation:forKey:？ 【发布时间】：2013-08-16 09:36:06 【问题描述】：

由于 UIView Animation 是由 CAAnimation 支持的，所以我猜，当 id do UIView animateWithDuration:animations 时，会触发 CALayer 的 addAnimation:forKey:。所以我做了一个方法 swizzling 并在其中输出一些信息。

#import "CALayer+Swizzling.h"
#import <objc/runtime.h>

@implementation CALayer (Swizzling)

+ (void)load

    method_exchangeImplementations(class_getInstanceMethod([CALayer class], @selector(addAnimation:forKey:)), class_getInstanceMethod([CALayer class], @selector(hackedAddAnimation:forKey:)));


- (void)hackedAddAnimation:(CAAnimation *)animation forKey:(NSString *)key

    [self hackedAddAnimation:animation forKey:key];
    if ([animation isKindOfClass:[CABasicAnimation class]]) 
        CABasicAnimation *basicAnimation = (CABasicAnimation *)animation;
        if ([basicAnimation.keyPath isEqualToString:@"transform"]) 
            CATransform3D transform = [basicAnimation.fromValue CATransform3DValue];
            if (basicAnimation.fromValue) 
                NSLog(@"fromValue:%@", NSStringFromCGAffineTransform(CATransform3DGetAffineTransform(transform)));
            
            if (basicAnimation.toValue) 
                NSLog(@"toValue:%@", NSStringFromCGAffineTransform(CATransform3DGetAffineTransform(transform)));
            
            if (basicAnimation.byValue) 
                NSLog(@"byValue:%@", NSStringFromCGAffineTransform(CATransform3DGetAffineTransform(transform)));
            
            NSLog(@"timingFunction:%@", basicAnimation.timingFunction);
            NSLog(@"duration:%f", basicAnimation.duration);
        
    

@end

什么也没发生。但如果我显示UIAlertView，它就会被触发。

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"title" message:@"" delegate:nil cancelButtonTitle:@"cancel" otherButtonTitles:@"", nil];

[alertView show];

这是结果：

2013-08-16 17:28:39.693 Test[81840:c07] fromValue:[0.01, 0, 0, 0.01, 0, 0]
2013-08-16 17:28:39.694 Test[81840:c07] timingFunction:easeInEaseOut
2013-08-16 17:28:39.695 Test[81840:c07] duration:0.200000
2013-08-16 17:28:39.897 Test[81840:c07] fromValue:[1.1, 0, 0, 1.1, 0, 0]
2013-08-16 17:28:39.897 Test[81840:c07] timingFunction:easeInEaseOut
2013-08-16 17:28:39.899 Test[81840:c07] duration:0.100000
2013-08-16 17:28:40.000 Test[81840:c07] fromValue:[0.9, 0, 0, 0.9, 0, 0]
2013-08-16 17:28:40.000 Test[81840:c07] timingFunction:easeInEaseOut
2013-08-16 17:28:40.001 Test[81840:c07] duration:0.100000

【问题讨论】：

【参考方案1】：

我假设它被视为图层上的隐式动画，在这种情况下，您将改用 actionForKey:。

【讨论】：

【参考方案2】：

你设置了动画的delegate 吗？