CAShapeLayer的使用[2]

CAShapeLayer的使用[2]

CAShapeLayer支持的动画类型有如下这些.

------------------------------------------------------------------------------

/* The path defining the shape to be rendered. If the path extends
 * outside the layer bounds it will not automatically be clipped to the
 * layer, only if the normal layer masking rules cause that. Defaults
 * to null. Animatable. (Note that although the path property is
 * animatable, no implicit animation will be created when the property
 * is changed.) */

@property CGPathRef path;

------------------------------------------------------------------------------

/* The color to fill the path's stroked outline, or nil for no stroking.
 * Defaults to nil. Animatable. */

@property CGColorRef strokeColor;

------------------------------------------------------------------------------

/* These values define the subregion of the path used to draw the
 * stroked outline. The values must be in the range [0,1] with zero
 * representing the start of the path and one the end. Values in
 * between zero and one are interpolated linearly along the path
 * length. strokeStart defaults to zero and strokeEnd to one. Both are
 * animatable. */

@property CGFloat strokeStart, strokeEnd;

------------------------------------------------------------------------------

/* The line width used when stroking the path. Defaults to one.
 * Animatable. */

@property CGFloat lineWidth;
------------------------------------------------------------------------------
/* The miter limit used when stroking the path. Defaults to ten.
 * Animatable. */

@property CGFloat miterLimit;

------------------------------------------------------------------------------

/* The phase of the dashing pattern applied when creating the stroke.
 * Defaults to zero. Animatable. */

@property CGFloat lineDashPhase;

------------------------------------------------------------------------------

现在来尝试path动画,结果如下:

首先用工具生成path源码:

源码:

- (void)viewDidLoad
{
    [super viewDidLoad];

    // shapeLayer
    CAShapeLayer *circleLayer = [CAShapeLayer layer];
    circleLayer.frame         = (CGRect){CGPointMake(, ), CGSizeMake(, )};
    circleLayer.position      = self.view.center;
    circleLayer.path          = [self getStar1BezierPath].CGPath;
    circleLayer.fillColor     = [UIColor clearColor].CGColor;
    circleLayer.strokeColor   = [UIColor redColor].CGColor;
    circleLayer.lineWidth     = .f;
    [self.view.layer addSublayer:circleLayer];

    // 定时器
    _timer = [[GCDTimer alloc] initInQueue:[GCDQueue mainQueue]];
    [_timer event:^{
        static int i = ;
        if (i++ %  == )
        {
            CABasicAnimation *circleAnim = [CABasicAnimation animationWithKeyPath:@"path"];
            circleAnim.removedOnCompletion = NO;
            circleAnim.duration  = ;
            circleAnim.fromValue = (__bridge id)[self getStar1BezierPath].CGPath;
            circleAnim.toValue   = (__bridge id)[self getStar2BezierPath].CGPath;
            circleLayer.path = [self getStar2BezierPath].CGPath;
            [circleLayer addAnimation:circleAnim forKey:@"animateCirclePath"];
        }
        else
        {
            CABasicAnimation *circleAnim = [CABasicAnimation animationWithKeyPath:@"path"];
            circleAnim.removedOnCompletion = NO;
            circleAnim.duration  = ;
            circleAnim.fromValue = (__bridge id)[self getStar2BezierPath].CGPath;
            circleAnim.toValue   = (__bridge id)[self getStar1BezierPath].CGPath;
            circleLayer.path = [self getStar1BezierPath].CGPath;
            [circleLayer addAnimation:circleAnim forKey:@"animateCirclePath"];
        }
    } timeInterval:NSEC_PER_SEC];
    [_timer start];
}

-(UIBezierPath *)getStar1BezierPath
{
    //// Star Drawing
    UIBezierPath* starPath = [UIBezierPath bezierPath];
    [starPath moveToPoint: CGPointMake(22.5, 2.5)];
    [starPath addLineToPoint: CGPointMake(28.32, 14.49)];
    [starPath addLineToPoint: CGPointMake(41.52, 16.32)];
    [starPath addLineToPoint: CGPointMake(31.92, 25.56)];
    [starPath addLineToPoint: CGPointMake(34.26, 38.68)];
    [starPath addLineToPoint: CGPointMake(22.5, 32.4)];
    [starPath addLineToPoint: CGPointMake(10.74, 38.68)];
    [starPath addLineToPoint: CGPointMake(13.08, 25.56)];
    [starPath addLineToPoint: CGPointMake(3.48, 16.32)];
    [starPath addLineToPoint: CGPointMake(16.68, 14.49)];
    [starPath closePath];

    return starPath;
}

-(UIBezierPath *)getStar2BezierPath
{
    //// Star Drawing
    UIBezierPath* starPath = [UIBezierPath bezierPath];
    [starPath moveToPoint: CGPointMake(22.5, 2.5)];
    [starPath addLineToPoint: CGPointMake(32.15, 9.21)];
    [starPath addLineToPoint: CGPointMake(41.52, 16.32)];
    [starPath addLineToPoint: CGPointMake(38.12, 27.57)];
    [starPath addLineToPoint: CGPointMake(34.26, 38.68)];
    [starPath addLineToPoint: CGPointMake(22.5, 38.92)];
    [starPath addLineToPoint: CGPointMake(10.74, 38.68)];
    [starPath addLineToPoint: CGPointMake(6.88, 27.57)];
    [starPath addLineToPoint: CGPointMake(3.48, 16.32)];
    [starPath addLineToPoint: CGPointMake(12.85, 9.21)];
    [starPath closePath];

    return starPath;
}

CALayer中有一个令人抽搐的属性叫mask,据说可以做动画,官方文档上说可以:

但其属性说明中根本就没有animatable字眼.

/* A layer whose alpha channel is used as a mask to select between the
 * layer's background and the result of compositing the layer's
 * contents with its filtered background. Defaults to nil. When used as
 * a mask the layer's `compositingFilter' and `backgroundFilters'
 * properties are ignored. When setting the mask to a new layer, the
 * new layer must have a nil superlayer, otherwise the behavior is
 * undefined. */

@property(retain) CALayer *mask;

这是个bug哦:).

将CAShapeLayer当做mask做动画的效果:

源码:

- (void)viewDidLoad
{
    [super viewDidLoad];

    // shapeLayer
    CAShapeLayer *circleLayer = [CAShapeLayer layer];
    circleLayer.frame         = (CGRect){CGPointMake(, ), CGSizeMake(, )};
    circleLayer.position      = self.view.center;
    circleLayer.path          = [self getStar1BezierPath].CGPath;
    circleLayer.fillColor     = [UIColor blackColor].CGColor;
    circleLayer.strokeColor   = [UIColor redColor].CGColor;
    circleLayer.lineWidth     = .f;

    // backgroundLayer
    CALayer *layer = [CALayer layer];
    layer.frame    = self.view.bounds;
    layer.contents = (__bridge id)([UIImage imageNamed:@"psb.jpg"].CGImage);
    layer.mask     = circleLayer;
    [self.view.layer addSublayer:layer];

    // 定时器
    _timer = [[GCDTimer alloc] initInQueue:[GCDQueue mainQueue]];
    [_timer event:^{
        static int i = ;
        if (i++ %  == )
        {
            CABasicAnimation *circleAnim = [CABasicAnimation animationWithKeyPath:@"path"];
            circleAnim.removedOnCompletion = NO;
            circleAnim.duration  = ;
            circleAnim.fromValue = (__bridge id)[self getStar1BezierPath].CGPath;
            circleAnim.toValue   = (__bridge id)[self getStar2BezierPath].CGPath;
            circleLayer.path = [self getStar2BezierPath].CGPath;
            [circleLayer addAnimation:circleAnim forKey:@"animateCirclePath"];
        }
        else
        {
            CABasicAnimation *circleAnim = [CABasicAnimation animationWithKeyPath:@"path"];
            circleAnim.removedOnCompletion = NO;
            circleAnim.duration  = ;
            circleAnim.fromValue = (__bridge id)[self getStar2BezierPath].CGPath;
            circleAnim.toValue   = (__bridge id)[self getStar1BezierPath].CGPath;
            circleLayer.path = [self getStar1BezierPath].CGPath;
            [circleLayer addAnimation:circleAnim forKey:@"animateCirclePath"];
        }
    } timeInterval:NSEC_PER_SEC];
    [_timer start];
}

-(UIBezierPath *)getStar1BezierPath
{
    //// Star Drawing
    UIBezierPath* starPath = [UIBezierPath bezierPath];
    [starPath moveToPoint: CGPointMake(22.5, 2.5)];
    [starPath addLineToPoint: CGPointMake(28.32, 14.49)];
    [starPath addLineToPoint: CGPointMake(41.52, 16.32)];
    [starPath addLineToPoint: CGPointMake(31.92, 25.56)];
    [starPath addLineToPoint: CGPointMake(34.26, 38.68)];
    [starPath addLineToPoint: CGPointMake(22.5, 32.4)];
    [starPath addLineToPoint: CGPointMake(10.74, 38.68)];
    [starPath addLineToPoint: CGPointMake(13.08, 25.56)];
    [starPath addLineToPoint: CGPointMake(3.48, 16.32)];
    [starPath addLineToPoint: CGPointMake(16.68, 14.49)];
    [starPath closePath];

    return starPath;
}

-(UIBezierPath *)getStar2BezierPath
{
    //// Star Drawing
    UIBezierPath* starPath = [UIBezierPath bezierPath];
    [starPath moveToPoint: CGPointMake(22.5, 2.5)];
    [starPath addLineToPoint: CGPointMake(32.15, 9.21)];
    [starPath addLineToPoint: CGPointMake(41.52, 16.32)];
    [starPath addLineToPoint: CGPointMake(38.12, 27.57)];
    [starPath addLineToPoint: CGPointMake(34.26, 38.68)];
    [starPath addLineToPoint: CGPointMake(22.5, 38.92)];
    [starPath addLineToPoint: CGPointMake(10.74, 38.68)];
    [starPath addLineToPoint: CGPointMake(6.88, 27.57)];
    [starPath addLineToPoint: CGPointMake(3.48, 16.32)];
    [starPath addLineToPoint: CGPointMake(12.85, 9.21)];
    [starPath closePath];

    return starPath;
}

附录:

用CAShapeLayer与贝塞尔曲线一起制作下载进度条是相当的容易的说:

//
//  RootViewController.m
//
//  Copyright (c) 2014年 Y.X. All rights reserved.
//

#import "RootViewController.h"
#import "YXGCD.h"

@interface RootViewController ()

@property (nonatomic, strong) GCDTimer *timer;

@end

@implementation RootViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // 获取path
    UIBezierPath *path = [self getBezierPathWithLength:300 lineWidth:1];
    
    // shapeLayer
    CAShapeLayer *circleLayer = [CAShapeLayer layer];
    circleLayer.frame         = path.bounds;
    circleLayer.position      = self.view.center;
    circleLayer.fillColor     = [UIColor clearColor].CGColor;
    circleLayer.strokeColor   = [UIColor redColor].CGColor;
    circleLayer.path          = path.CGPath;
    circleLayer.lineWidth     = 1.f;
    [self.view.layer addSublayer:circleLayer];
    
    // 定时器
    _timer = [[GCDTimer alloc] initInQueue:[GCDQueue mainQueue]];
    [_timer event:^{

circleLayer.strokeEnd = arc4random()%100/100.f;
        
    } timeInterval:NSEC_PER_SEC];
    [_timer start];
}

-(UIBezierPath *)getBezierPathWithLength:(CGFloat)length lineWidth:(CGFloat)lineWidth
{
    //// Bezier Drawing
    UIBezierPath* bezierPath = [UIBezierPath bezierPath];
    [bezierPath moveToPoint: CGPointMake(0, 0)];
    [bezierPath addLineToPoint: CGPointMake(length, 0)];
    bezierPath.lineWidth = lineWidth;
    
    return bezierPath;
}

@end