IOS animation activity indicator

IOS animation activity indicator
1. Result Display

2. Implementation ideas

1. Create a copy Layer

    CAReplicatorLayer *replicator = [CAReplicatorLayer layer];    replicator.frame = CGRectMake(50, 50, 200, 200);    replicator.backgroundColor = [UIColor redColor].CGColor;    [self.view.layer addSublayer:replicator];

2. Create a rectangular layer and set the scaling animation.

    CALayer *indicator = [CALayer layer];    indicator.transform = CATransform3DMakeScale(0, 0, 0);    indicator.position = CGPointMake(100, 20);    indicator.bounds = CGRectMake(0, 0, 10, 10);    indicator.backgroundColor = [UIColor greenColor].CGColor;    [replicator addSublayer:indicator];    CGFloat durtion = 1;    CABasicAnimation *anim = [CABasicAnimation animation];    anim.keyPath = @"transform.scale";    anim.fromValue = @1;    anim.toValue = @0.1;    anim.repeatCount = MAXFLOAT;    anim.duration = durtion;    [indicator addAnimation:anim forKey:nil];

3. Copy the rectangular layer and set the angle deformation of each copy layer.

Int count = 10; // set the number of child layers replicator. instanceCount = count; // sets the child layer deformation angle CGFloat angle = M_PI * 2/count; replicator. instanceTransform = CATransform3DMakeRotation (angle, 0, 0, 1 );

4. Set the extension time of the copy animation. After the first animation is executed, the animation duration must be evenly distributed to each child layer)
Formula: Extend time = animation duration/total number of child Layers

If there are two layers, the animation time is 1 second, and the extension time is 0.5 seconds. When the first animation is half executed (0.5), the second animation starts to be executed. The second execution is complete.

// Set the child layer animation extension time replicator. instanceDelay = durtion/count;

3. complete code

# Import "ViewController. h "# define Count 20.0 # define DurationTime 1.0 @ interface ViewController () @ property (nonatomic, strong) CAReplicatorLayer * replicator; @ property (nonatomic, strong) CALayer * indicator; @ property (nonatomic, strong) CABasicAnimation * anim; @ end @ implementation ViewController // lazy loading, replication layer-(CAReplicatorLayer *) replicator {if (_ replicator = nil) {_ replicator = [CAReplicatorLayer]; _ replicator. frame = CGRectMake (50, 50,200,200); _ replicator. backgroundColor = [UIColor clearColor]. CGColor; // set the number of child layers _ replicator. instanceCount = Count; // sets the child animation extension time _ replicator. instanceDelay = DurationTime/Count; // sets the child layer deformation angle CGFloat angle = M_PI * 2/Count; _ replicator. instanceTransform = CATransform3DMakeRotation (angle, 0, 0, 1);} return _ replicator;} // common layer-(CALayer *) indicator {if (_ indicator = nil) {_ indicator = [CALayer layer]; _ indicator. transform = CATransform3DMakeScale (0, 0, 0); _ indicator. position = CGPointMake (100, 20); _ indicator. bounds = CGRectMake (0, 0, 10, 10); _ indicator. cornerRadius = 5; _ indicator. backgroundColor = [UIColor greenColor]. CGColor;} return _ indicator;} // animation-(CABasicAnimation *) anim {if (_ anim = nil) {_ anim = [CABasicAnimation animation]; _ anim. keyPath = @ "transform. scale "; _ anim. fromValue = @ 1; _ anim. toValue = @ 0.1; _ anim. repeatCount = MAXFLOAT; _ anim. duration = DurationTime;} return _ anim;}-(void) viewDidLoad {[super viewDidLoad]; // Add the replication layer [self. view. layer addSublayer: self. replicator]; // Add layer [self. replicator addSublayer: self. indicator]; // Add an animation [self. indicator addAnimation: self. anim forKey: nil] ;}@ end