我正在测试这个项目：https ://github.com/devindoty/iBooks-Flip-Animation ，我注意到截屏时内存分配的增加。
当我分析该应用程序时，我看到将在 CALayer renderInContext 中分配大量内存。原因似乎是CGContextDrawImage。但是如何解决呢？
我将在此处粘贴必要的代码：
@implementation iBookAnimationViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
self.view.layer.contents = (id)[UIImage imageNamed:@"Shelf_Contents@2x.png"].CGImage;
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(flip:)];
[self.view addGestureRecognizer:gesture];
[gesture release];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark -
#pragma mark Gesture
- (void)flip:(UIGestureRecognizer*)gesture{
FlipSideViewController *controller = [[FlipSideViewController alloc] init];
controller.delegate = (id<FlipSideDelegate>)self;
[self presentModalViewController:controller animated:YES];
[controller release];
}
#pragma mark -
#pragma mark Animation Methods
- (CATransform3D)transformWithDegrees:(CGFloat)degrees{
if (degrees == 0) {
return CATransform3DIdentity;
}
return CATransform3DMakeRotation((M_PI/180)*degrees, 0.0f, 1.0f, 0.0);
}
- (UIImage*)contentsForView:(UIView*)aView{
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, YES, [[UIScreen mainScreen] scale]);
[aView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
if (flag) {
[[anim valueForKey:@"ContentsLayer"] removeFromSuperlayer];
[[UIApplication sharedApplication] endIgnoringInteractionEvents];
}
}
- (void)animateFromViewController:(UIViewController*)fromController toViewController:(UIViewController*)toController{
UIImage *image = [self contentsForView:toController.view];
CALayer *contentsLayer = [CALayer layer];
contentsLayer.frame = toController.view.bounds;
contentsLayer.backgroundColor = [UIColor blackColor].CGColor;
[toController.view.layer addSublayer:contentsLayer];
CATransformLayer *transformLayer = [CATransformLayer layer];
transformLayer.frame = contentsLayer.bounds;
[contentsLayer addSublayer:transformLayer];
CALayer *backLayer = [CALayer layer];
backLayer.contents = (id)image.CGImage;
backLayer.doubleSided = NO;
backLayer.frame = transformLayer.bounds;
backLayer.zPosition = 0.0f;
backLayer.transform = [self transformWithDegrees:180.0f];
[transformLayer addSublayer:backLayer];
CALayer *frontLayer = [CALayer layer];
frontLayer.contents = (id)[self contentsForView:fromController.view].CGImage;
frontLayer.doubleSided = NO;
frontLayer.zPosition = FLIP_GAP;
frontLayer.frame = transformLayer.bounds;
frontLayer.masksToBounds = NO;
[transformLayer addSublayer:frontLayer];
CALayer *sideLayer = [CALayer layer];
sideLayer.contents = (id)[UIImage imageNamed:@"Wood Tile.png"].CGImage;
sideLayer.zPosition = FLIP_GAP/2;
sideLayer.frame = CGRectMake(transformLayer.bounds.origin.x-(FLIP_GAP/2), transformLayer.bounds.origin.y, FLIP_GAP, transformLayer.bounds.size.height);
sideLayer.transform = [self transformWithDegrees:90.0f];
[transformLayer addSublayer:sideLayer];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"sublayerTransform"];
animation.toValue = [NSValue valueWithCATransform3D:[self transformWithDegrees:179.9f]];
animation.duration = ANIMATION_DURATION;
animation.fillMode = kCAFillModeForwards;
animation.removedOnCompletion = NO;
animation.delegate = self;
[animation setValue:contentsLayer forKey:@"ContentsLayer"];
[transformLayer addAnimation:animation forKey:@"FlipAnimation"];
[[UIApplication sharedApplication] beginIgnoringInteractionEvents];
}
#pragma mark -
#pragma mark Modal Prentation Methods
- (void)dismissModalViewControllerAnimated:(BOOL)animated{
UIViewController *modalViewController = self.modalViewController;
[self animateFromViewController:modalViewController toViewController:self];
[super dismissModalViewControllerAnimated:NO];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque animated:YES];
}
- (void)presentModalViewController:(UIViewController *)modalViewController animated:(BOOL)animated{
[super presentModalViewController:modalViewController animated:NO];
[self animateFromViewController:self toViewController:modalViewController];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault animated:YES];
}
#pragma mark -
#pragma mark FlipSideDelegate
- (void)dismissFlipSideViewController:(FlipSideViewController*)controller{
[self dismissModalViewControllerAnimated:YES];
}
#pragma mark -
#pragma mark Memory Management
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)viewDidUnload {
}
- (void)dealloc {
[super dealloc];
}
@end