在ios中运用core animation暂停和继续动画

<pre name="code" class="cpp">//暂停layer上面的动画

- (void)pauseLayer:(CALayer*)layer

{

CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];

layer.speed = 0.0;

layer.timeOffset = pausedTime;

}

//继续layer上面的动画

- (void)resumeLayer:(CALayer*)layer

{

CFTimeInterval pausedTime = [layer timeOffset];

layer.speed = 1.0;

layer.timeOffset = 0.0;

layer.beginTime = 0.0;

CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;

layer.beginTime = timeSincePause;

}</pre><br>

<pre></pre>

<p>附上完整代码</p>

<p></p>

<p class="p1">AnimationPauseViewController.h</p>

<pre name="code" class="cpp">#import <UIKit/UIKit.h>

@interface AnimationPauseViewController : UIViewController {

UIImageView *soccer;

BOOL isPause;

UIButton *controlButton;

}

@property (nonatomic, retain) IBOutlet UIImageView *soccer;

- (IBAction)clickControlButton:(id)sender;

@property (nonatomic, retain) IBOutlet UIButton *controlButton;

@end</pre><br>

<p></p>

<p class="p1">AnimationPauseViewController.m</p>

<p></p><pre name="code" class="cpp">#import "AnimationPauseViewController.h"

#import <QuartzCore/QuartzCore.h>

@implementation AnimationPauseViewController

@synthesize controlButton;

@synthesize soccer;

- (void)dealloc

{

[soccer release];

[controlButton release];

[super dealloc];

}

- (void)didReceiveMemoryWarning

{

// Releases the view if it doesn't have a superview.

[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.

}

- (void)addAnimations

{

//让足球来回移动

CABasicAnimation *translation = [CABasicAnimation animationWithKeyPath:@"position"];

translation.fromValue = [NSValue valueWithCGPoint:CGPointMake(24, 240)];

translation.toValue = [NSValue valueWithCGPoint:CGPointMake(320- 24, 240)];

translation.duration = 2;

translation.repeatCount = HUGE_VALF;

translation.autoreverses = YES;

//让足球来回转动

CABasicAnimation *rotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

//kCAMediaTimingFunctionLinear 表示时间方法为线性，使得足球匀速转动

rotation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];

rotation.toValue = [NSNumber numberWithFloat:4 * M_PI];

rotation.duration = 2;

rotation.repeatCount = HUGE_VALF;

rotation.autoreverses = YES;

[soccer.layer addAnimation:rotation forKey:@"rotation"];

[soccer.layer addAnimation:translation forKey:@"translation"];

}

#pragma mark - View lifecycle

- (void)viewDidLoad

{

[super viewDidLoad];

[self addAnimations];

}

- (void)viewDidUnload

{

[self setSoccer:nil];

[self setControlButton:nil];

[super viewDidUnload];

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

// Return YES for supported orientations

return (interfaceOrientation == UIInterfaceOrientationPortrait);

}

//暂停layer上面的动画

- (void)pauseLayer:(CALayer*)layer

{

CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];

layer.speed = 0.0;

layer.timeOffset = pausedTime;

}

//继续layer上面的动画

- (void)resumeLayer:(CALayer*)layer

{

CFTimeInterval pausedTime = [layer timeOffset];

layer.speed = 1.0;

layer.timeOffset = 0.0;

layer.beginTime = 0.0;

CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;

layer.beginTime = timeSincePause;

}

- (void)pauseSoccer

{

isPause = YES;

[controlButton setTitle:@"继续" forState:UIControlStateNormal];

[self pauseLayer:soccer.layer];

}

- (void)resumeSoccer

{

isPause = NO;

[controlButton setTitle:@"暂停" forState:UIControlStateNormal];

[self resumeLayer:soccer.layer];

}

- (IBAction)clickControlButton:(id)sender {

if (isPause) {

[self resumeSoccer];

}else{

[self pauseSoccer];

}

}

@end</pre><br>

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