ios – 使用CADisplayLink’结合’与CAMediaTimingFunction动画UIView. (获得任意曲线)

有这个令人敬畏的要点 RSTiming,在你的情况下可能会很方便.您可以使用标准CAMediaTimingFunction定义定时功能,甚至可以使用2个控制点定义定制功能来定义贝塞尔曲线.

如果我得到你的设置,你可能会有这样的事情：

视图控制器

#import "ViewController.h"
#import "AnimatedView.h"
#include <stdlib.h>

@interface ViewController ()

@property (nonatomic,strong) CADisplayLink *displayLink;
@property (weak,nonatomiC) IBOutlet AnimatedView *viewToAnimate;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    self.displayLink = [CADisplayLink displayLinkWithTarget:self SELEctor:@SELEctor(updateFramE)];
    [self.displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
}

- (void)updateFrame {
    [self.viewToAnimate updateAnimation];
}

- (IBACtion)updateAnimationTapped:(id)sender {
    self.viewToAnimate.value = arc4random_uniform(101) / 100.0;
    NSLog(@"Next animation value: %f",self.viewToAnimate.value);
}

@end

AnimatedView

#import "AnimatedView.h"
#import "RSTimingFunction.h"

@interface AnimatedView()
{
    CGFloat _lastValue;
    CGFloat _progressStep;
    CGFloat _currentProgress;
}

@property (nonatomic,strong) RSTimingFunction *animationProgress;

@end

@implementation AnimatedView

- (instanCETypE)initWithCoder:(NSCoder *)aDecoder
{
    if ((self = [super initWithCoder:aDecoder]))
    {
        _progressStep = 0.01; // defines animation speed
        _currentProgress = 1.0;
        self.animationProgress = [RSTimingFunction timingFunctionWithName:kRSTimingFunctionEaseInEaSEOut];
    }

    return self;
}

- (void)SETVALue:(CGFloat)value {
    if (_value != value)
    {
        _lastValue = _value;
        _value = value;
        _currentProgress = 0.0;
    }
}

- (void)updateAnimation
{
    if (_currentProgress > 1.0)
        return;

    _currentProgress += _progressStep;
    CGFloat currentAnimationValue = _lastValue + (_value - _lastvalue) * [self.animationProgress valueForX:_currentProgress];

    self.alpha = currentAnimationValue; // as an example animate alpha
}

@end

如上所述,您甚至可以设置2个控制点来创建以三次贝塞尔曲线为模型的定时函数.

self.animationProgress = [RSTimingFunction timingFunctionWithControlPoint1:CGPointMake(0.6,0.6) controlPoint2:CGPointMake(0.1,0.8)];

这将产生以下时间动画(使用CAMediaTimingFunction playground制作)