如何轻松使用标准变量计时功能

Question

我想知道是否有办法在应用程序中快速使用更多不同的计时功能。例如，使用Robert Penner's，许多工具包暴露它们，我很惊讶Apple没有。

基本上是一种让基于块的命令像animateWithDuration一样灵活的方法：delay：options：animations：completion：in UIView。

我想出了这个解决方案，很高兴知道是否有更好的选择。

//  UIView+CustomTimingFunction.h
#import <UIKit/UIKit.h>

typedef enum {
    CustomTimingFunctionDefault,
    CustomTimingFunctionLinear,
    CustomTimingFunctionEaseIn,
    CustomTimingFunctionEaseOut,
    ....
} CustomTimingFunction;

@interface UIView (CustomTimingFunction)

- (void)animateProperty:(NSString *)property from:(id)from to:(id)to withDuration:(NSTimeInterval)duration customTimingFunction:(CustomTimingFunction)customTimingFunction competion:(void (^)(void))competion;

@end

和

//  UIView+CustomTimingFunction.m

#import "UIView+CustomTimingFunction.h"

@implementation UIView (CustomTimingFunction)

- (void)animateProperty:(NSString *)property from:(id)from to:(id)to withDuration:(NSTimeInterval)duration customTimingFunction:(CustomTimingFunction)customTimingFunction competion:(void (^)(void))competion
{
    [CATransaction begin]; {
        [CATransaction setCompletionBlock:competion];

        if([property isEqualToString:@"frame"]){
            CGRect fromRect = [from CGRectValue];
            CGPoint fromPosition = CGPointMake(CGRectGetMidX(fromRect), CGRectGetMidY(fromRect));
            CGRect toRect = [to CGRectValue];
            CGPoint toPosition = CGPointMake(CGRectGetMidX(toRect), CGRectGetMidY(toRect));

            CABasicAnimation *positionAnimation = [CABasicAnimation animationWithKeyPath:@"position"];
            positionAnimation.timingFunction = [[self class] functionWithType:customTimingFunction];
            positionAnimation.fromValue = [NSValue valueWithCGPoint:fromPosition];
            positionAnimation.toValue = [NSValue valueWithCGPoint:toPosition];

            CABasicAnimation *boundsAnimation = [CABasicAnimation animationWithKeyPath:@"bounds"];
            boundsAnimation.timingFunction = [[self class] functionWithType:customTimingFunction];
            boundsAnimation.fromValue = from;
            boundsAnimation.toValue = to;

            CAAnimationGroup * group =[CAAnimationGroup animation];
            group.removedOnCompletion=NO;
            group.fillMode=kCAFillModeForwards;
            group.animations = @[positionAnimation,boundsAnimation];
            group.duration = duration;

            [self.layer addAnimation:group forKey:property];
        }else{
            CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:property];
            animation.duration = duration;
            animation.timingFunction = [[self class] functionWithType:customTimingFunction];
            animation.fillMode = kCAFillModeForwards;
            animation.removedOnCompletion = NO;
            animation.fromValue = from;
            animation.toValue = to;
            [self.layer addAnimation:animation forKey:animation.keyPath];
        }
    } [CATransaction commit];

}

+(CAMediaTimingFunction *)functionWithType:(CustomTimingFunction)type
{
    switch (type) {
        case CustomTimingFunctionDefault:
            return [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault];
            break;
        case CustomTimingFunctionLinear:
            return [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
            break;

        case CustomTimingFunctionEaseIn:
            return [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
            break;
        case CustomTimingFunctionEaseOut:
            return [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
            break;
        case CustomTimingFunctionEaseInOut:
            return [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
            break;

        ....
    }

    NSLog(@"Couldn't find CustomTimingFunction, will return linear");
    return [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
}

@end

谢谢！