Question

我正在测试该项目：https://github.com/devindoty/iBooks-Flip-Animation 我在拍摄截图时注意到了越来越多的记忆分配。

当我分析该应用程序时，我发现将在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

Answer 1

尝试使用带有“内存泄漏”工具的仪器运行您的确切用例。它可能会指向你的吸烟枪，他们很难追查。此外，我总是建议bbum在堆分析方面的优秀链接（过去已经保存了我的培根）。 http://www.friday.com/bbum/2010/10/17/when-is-a-leak-not-a-leak-using-heapshot-analysis-to-find-undesirable-memory-growth/

屏幕截图的ios内存分配问题

1 个答案: