酷炫登录动画效果

登录效果：

登录界面背景使用CAGradientLayer实现，动画主要使用CAShapeLayer和UIBezierPath组合来实现，通过UIBezierPath改变CAShapeLayer的path实现形变动画，通过opacity实现渐变消失动画，有兴趣的朋友可以前往github下载查看，喜欢可以star谢谢！这里贴出登录按钮动画核心代码：

#import "LRButton.h"

@interface LRButton()

//渲染层
@property (nonatomic,strong) CAShapeLayer *maskLayer;

@property (nonatomic,strong) CAShapeLayer *shapeLayer;

@property (nonatomic,strong) CAShapeLayer *loadingLayer;

@property (nonatomic,strong) CAShapeLayer *clickCicrleLayer;

@property (nonatomic,strong) UIButton *button;

@end


@implementation LRButton

-(instancetype)initWithFrame:(CGRect)frame{
    if(self = [super initWithFrame:frame]){
        _shapeLayer = [self drawMask:frame.size.height/2];
        _shapeLayer.fillColor = [UIColor clearColor].CGColor;
        _shapeLayer.strokeColor = [UIColor whiteColor].CGColor;
        _shapeLayer.lineWidth = 2;
        [self.layer addSublayer:_shapeLayer];
        
        [self.layer addSublayer:self.maskLayer];
        
        _button = [UIButton buttonWithType:UIButtonTypeCustom];
        _button.frame = self.bounds;
        [_button setTitle:@"SIGN IN" forState:UIControlStateNormal];
        [_button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        _button.titleLabel.font = [UIFont systemFontOfSize:13.f];
        [self addSubview:_button];
        [_button addTarget:self action:@selector(clickBtn) forControlEvents:UIControlEventTouchUpInside];
    }
    return self;
}

-(CAShapeLayer *)maskLayer{
    if(!_maskLayer){
        _maskLayer = [CAShapeLayer layer];
        _maskLayer.opacity = 0;
        _maskLayer.fillColor = [UIColor whiteColor].CGColor;
        _maskLayer.path = [self drawBezierPath:self.frame.size.width/2].CGPath;
    }
    return _maskLayer;
}

-(void)layoutSubviews{
    [super layoutSubviews];
    
}


///按钮点击
-(void)clickBtn{
    [self clickAnimation];
}

-(void)clickAnimation{
    CAShapeLayer *clickCicrleLayer = [CAShapeLayer layer];
    clickCicrleLayer.position = CGPointMake(self.bounds.size.width/2, self.bounds.size.height/2);
    clickCicrleLayer.fillColor = [UIColor whiteColor].CGColor;
    clickCicrleLayer.path = [self drawclickCircleBezierPath:0].CGPath;
    [self.layer addSublayer:clickCicrleLayer];
    
    CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"path"];
    basicAnimation.duration = 0.15;
    basicAnimation.toValue = (__bridge id _Nullable)([self drawclickCircleBezierPath:(self.bounds.size.height - 10*2)/2].CGPath);
    basicAnimation.removedOnCompletion = NO;
    basicAnimation.fillMode = kCAFillModeForwards;

    [clickCicrleLayer addAnimation:basicAnimation forKey:@"clickCicrleAnimation"];
    
    _clickCicrleLayer = clickCicrleLayer;
    
    [self performSelector:@selector(clickNextAnimation) withObject:self afterDelay:basicAnimation.duration];
}

-(void)clickNextAnimation{
    _clickCicrleLayer.fillColor = [UIColor clearColor].CGColor;
    _clickCicrleLayer.strokeColor = [UIColor whiteColor].CGColor;
    _clickCicrleLayer.lineWidth = 10;
    
    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
    //绘制大圆半径 self.bounds.size.height - 10*2
    CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"path"];
    basicAnimation.duration = 0.15;
    basicAnimation.toValue = (__bridge id _Nullable)([self drawclickCircleBezierPath:(self.bounds.size.height - 10*2)].CGPath);
    basicAnimation.removedOnCompletion = NO;
    basicAnimation.fillMode = kCAFillModeForwards;
    
    CABasicAnimation *basicAnimation1 = [CABasicAnimation animationWithKeyPath:@"opacity"];
    basicAnimation1.beginTime = 0.10;
    basicAnimation1.duration = 0.15;
    basicAnimation1.toValue = @0;
    basicAnimation1.removedOnCompletion = NO;
    basicAnimation1.fillMode = kCAFillModeForwards;
    
    animationGroup.duration = basicAnimation1.beginTime + basicAnimation1.duration;
    animationGroup.removedOnCompletion = NO;
    animationGroup.fillMode = kCAFillModeForwards;
    animationGroup.animations = @[basicAnimation,basicAnimation1];
    
    [_clickCicrleLayer addAnimation:animationGroup forKey:@"clickCicrleAnimation1"];

    [self performSelector:@selector(startMaskAnimation) withObject:self afterDelay:animationGroup.duration];
    
}

-(void)startMaskAnimation{
    _maskLayer.opacity = 0.15;
    CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"path"];
    basicAnimation.duration = 0.25;
    //绘制按钮形状
    basicAnimation.toValue = (__bridge id _Nullable)([self drawBezierPath:self.frame.size.height/2].CGPath);
    basicAnimation.removedOnCompletion = NO;
    basicAnimation.fillMode = kCAFillModeForwards;
    [_maskLayer addAnimation:basicAnimation forKey:@"maskAnimation"];
    
    [self performSelector:@selector(dismissAnimation) withObject:self afterDelay:basicAnimation.duration+0.2];
}

-(void)dismissAnimation{
    [self removeSubViews];
    
    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
    
    CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"path"];
    basicAnimation.duration = 0.15;
    //变成一个圆
    basicAnimation.toValue = (__bridge id _Nullable)([self drawBezierPath:self.frame.size.width/2].CGPath);
    basicAnimation.removedOnCompletion = NO;
    basicAnimation.fillMode = kCAFillModeForwards;
    
    CABasicAnimation *basicAnimation1 = [CABasicAnimation animationWithKeyPath:@"opacity"];
    basicAnimation1.beginTime = 0.10;
    basicAnimation1.duration = 0.15;
    basicAnimation1.toValue = @0;
    basicAnimation1.removedOnCompletion = NO;
    basicAnimation1.fillMode = kCAFillModeForwards;
    
    animationGroup.animations = @[basicAnimation,basicAnimation1];
    animationGroup.duration = basicAnimation1.beginTime+basicAnimation1.duration;
    animationGroup.removedOnCompletion = NO;
    animationGroup.fillMode = kCAFillModeForwards;
    [_shapeLayer addAnimation:animationGroup forKey:@"dismissAnimation"];
    
    [self performSelector:@selector(loadingAnimation) withObject:self afterDelay:animationGroup.duration];
}



-(void)loadingAnimation{
    
    //旋转圆弧
    _loadingLayer = [CAShapeLayer layer];
    _loadingLayer.position = CGPointMake(self.bounds.size.width/2, self.bounds.size.height/2);
    _loadingLayer.fillColor = [UIColor clearColor].CGColor;
    _loadingLayer.strokeColor = [UIColor whiteColor].CGColor;
    _loadingLayer.lineWidth = 2;
    //绘制圆弧
    _loadingLayer.path = [self drawLoadingBezierPath].CGPath;
    [self.layer addSublayer:_loadingLayer];

    CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    basicAnimation.fromValue = @(0);
    basicAnimation.toValue = @(M_PI*2);
    basicAnimation.duration = 0.5;
    basicAnimation.repeatCount = LONG_MAX;
    [_loadingLayer addAnimation:basicAnimation forKey:@"loadingAnimation"];
    
    [self performSelector:@selector(removeAllAnimation) withObject:self afterDelay:3];

}

-(void)removeAllAnimation{
    [self removeSubViews];
    if(self.translateBlock){
        self.translateBlock();
    }
}

-(void)removeSubViews{
    [_button removeFromSuperview];
    [_maskLayer removeFromSuperlayer];
    [_loadingLayer removeFromSuperlayer];
    [_clickCicrleLayer removeFromSuperlayer];
}

-(CAShapeLayer *)drawMask:(CGFloat)x{
    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    shapeLayer.frame = self.bounds;
    shapeLayer.path = [self drawBezierPath:x].CGPath;
    return shapeLayer;
}

-(UIBezierPath *)drawBezierPath:(CGFloat)x{
    CGFloat radius = self.bounds.size.height/2 - 3;
    CGFloat rightCenterX = self.bounds.size.width-x;
    CGFloat leftCenterX = x;
    NSLog(@"leftCenterX = %lf rightCenterX = %lf radius = %lf",leftCenterX,rightCenterX,radius);
    UIBezierPath *bezierPath = [UIBezierPath bezierPath];
    bezierPath.lineJoinStyle = kCGLineJoinRound;
    bezierPath.lineCapStyle = kCGLineCapRound;
    
    [bezierPath addArcWithCenter:CGPointMake(rightCenterX, self.bounds.size.height/2) radius:radius startAngle:-M_PI/2 endAngle:M_PI/2 clockwise:YES];
    [bezierPath addArcWithCenter:CGPointMake(leftCenterX, self.bounds.size.height/2) radius:radius startAngle:M_PI/2 endAngle:-M_PI/2 clockwise:YES];
    [bezierPath closePath];
    
    return bezierPath;
}


-(UIBezierPath *)drawLoadingBezierPath{
    CGFloat radius = self.bounds.size.height/2 - 3;
    UIBezierPath *bezierPath = [UIBezierPath bezierPath];
    [bezierPath addArcWithCenter:CGPointMake(0,0) radius:radius startAngle:M_PI/2 endAngle:M_PI/2+M_PI/2 clockwise:YES];
    return bezierPath;
}

-(UIBezierPath *)drawclickCircleBezierPath:(CGFloat)radius{
    UIBezierPath *bezierPath = [UIBezierPath bezierPath];
    [bezierPath addArcWithCenter:CGPointMake(0,0) radius:radius startAngle:0 endAngle:M_PI*2 clockwise:YES];
    return bezierPath;
}
@end