动画-复制层(CAReplicatorLayer)
2018-06-11 本文已影响2人
杭城小刘
音量柱动画效果图对于下面的效果大家是否有实现思路?
有些人可能要说:老夫撸起袖子,敲键盘就是干,不需要手势交互,那么直接用5个CALayer,处理不同的位置以及定时器、透明度等等,貌似很简单。
不不不,今天要带出来的主题是 CAReplicatorLayer
1、CAReplicatorLayer
/* The replicator layer creates a specified number of copies of its
- sublayers, each copy potentially having geometric, temporal and
- color transformations applied to it.
- Note: the CALayer -hitTest: method currently only tests the first
- instance of z replicator layer's sublayers. This may change in the
- future. */
官方给出的意思就不翻译了,使用场景大致是一个形状、特性差不多的 layer,我们不需要重复创建,可以利用它来实现复制多个 layer ,然后通过 CAReplicatorLayer 的一些属性实现我们的需求。
上述效果的代码
//创建复制层,因为我们做的多个音量柱变化的动画都是一样的,所以创建了一个复制层,这个复制层可以对里面的 sublayer 进行复制,所以我们不需要重复创建了
CAReplicatorLayer *replicatorrLayer = [CAReplicatorLayer layer];
replicatorrLayer.frame = CGRectMake(0, 0, self.contentView.frame.size.width, self.contentView.frame.size.height);
replicatorrLayer.backgroundColor = [UIColor blackColor].CGColor;
self.replicatorrLayer = replicatorrLayer;
[self.contentView.layer addSublayer:replicatorrLayer];
//创建音量震动条
CALayer *layer = [CALayer layer];
layer.backgroundColor = [UIColor whiteColor].CGColor;
CGFloat width = 30;
CGFloat height = 100;
layer.bounds = CGRectMake(0, self.contentView.frame.size.height - height, width, height);
layer.anchorPoint = CGPointMake(0, 1);
layer.position = CGPointMake(0, self.contentView.frame.size.height);
[self.contentView.layer addSublayer:layer];
//创建音量震动动画
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale.y"];
animation.toValue = @0;
animation.duration = 1;
animation.repeatCount = MAXFLOAT;
animation.autoreverses = YES;
[layer addAnimation:animation forKey:nil];
[replicatorrLayer addSublayer:layer];
//* The number of copies to create, including the source object.
replicatorrLayer.instanceCount = 6; //复制 sublayer 的个数,包括创建的第一个sublayer 在内的个数
replicatorrLayer.instanceDelay = 0.4; //设置动画延迟执行的时间
replicatorrLayer.instanceAlphaOffset = -0.15; //设置透明度递减
replicatorrLayer.instanceTransform = CATransform3DMakeTranslation(50, 0, 0);
例子1
倒影效果这里比较简单了,关键代码
CAReplicatorLayer *replicatorLayer = (CAReplicatorLayer *)self.view.layer;
replicatorLayer.instanceCount = 2;
replicatorLayer.instanceTransform = CATransform3DMakeRotation(M_PI, 1, 0, 0);
replicatorLayer.instanceRedOffset -= 0.1;
replicatorLayer.instanceGreenOffset -= 0.1;
replicatorLayer.instanceBlueOffset -= 0.1;
replicatorLayer.instanceAlphaOffset -= 0.3;
- 需要说明是这里我用 storyboard 处理的,因为已经拉好了控件,所以我们没办法将图片直接加到复制层上去。间接做法是将 UIViewController 的 view 的 layer 类型改变为 复制层
//该方法返回 UIView 的层
//改写 UIView 的层:重写 layerClass 方法
+ (Class)layerClass{
return [CAReplicatorLayer class];
}
例子2
复制层动画综合应用需求分析:
-
先画图。也就是添加一个滑动手势并监听它。然后强制绘图(self setNeedsDisplay)
-
添加一个 layer 到 self.layer 上
-
改变当前 view 的 layer 类型。
+ (Class)layerClass{
return [CAReplicatorLayer class];
}
-
设置 CAReplicatorLayer 的 instanceCount 和 instanceDelay 属性
-
添加了小点,并为小点设置关键帧动画。
-
重置功能实现靠的是清除 path 上面的 points ,并移除 小点上面的动画
#import "ViewControllerView.h"
@interface ViewControllerView()
@property (nonatomic, strong) UIBezierPath *path;
@property (nonatomic, weak) CALayer *dotLayer;
@end
@implementation ViewControllerView
+ (Class)layerClass{
return [CAReplicatorLayer class];
}
- (void)awakeFromNib{
[super awakeFromNib];
UIPanGestureRecognizer *tapGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(draw:)];
[self addGestureRecognizer:tapGesture];
self.path = [UIBezierPath bezierPath];
CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(-UIScreen.mainScreen.bounds.size.width, 0, 15, 15);
layer.backgroundColor = [UIColor colorWithRed:255/255.0 green:192/255.0 blue:203/255.0 alpha:1].CGColor;
layer.cornerRadius = 7.5;
self.dotLayer = layer;
[self.layer addSublayer:layer];
CAReplicatorLayer *replicatorLayer = (CAReplicatorLayer *)self.layer;
replicatorLayer.instanceCount = 20;
replicatorLayer.instanceDelay = 0.25;
}
- (void)draw:(UIPanGestureRecognizer *)tap{
CGPoint currentPoint = [tap locationInView:self];
if (tap.state == UIGestureRecognizerStateBegan) {
[self.path moveToPoint:currentPoint];
}
else if(tap.state == UIGestureRecognizerStateChanged){
[self.path addLineToPoint:currentPoint];
[self setNeedsDisplay];
}
}
- (void)startAnimation{
//要实现动画围绕着给定的形状执行,那么需要关键帧动画(类比于Flash概念中的关键帧动画,只需要给定指定的关键帧,其余的帧系统会创建出来。)。关键帧动画的 path 和 values 是互斥的,也就是说如果设置了 values 还设置了 path 那么 path 属性会覆盖 values 属性。
CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];
animation.keyPath = @"position";
animation.path = self.path.CGPath;
animation.duration = 5;
animation.repeatCount = MAXFLOAT;
[self.dotLayer addAnimation:animation forKey:nil];
}
- (void)redraw{
//清空路径:移除 path 上面所有的点,然后重绘
[self.path removeAllPoints];
[self setNeedsDisplay];
//移除动画
[self.dotLayer removeAllAnimations];
}
- (void)drawRect:(CGRect)rect{
[self.path stroke];
}
@end
CALayer 层的动画有2个概念非常重要:AnchorPoint 和 position
-
postion 用来确定 layer 层在父层中的位置
-
anchorPoint 用来确定 layer 身上哪个点会在 position 所指的位置。