我在使用 ARC 的 iPhone 应用程序中遇到了一个相当严重的问题。
我有一个视图控制器（让我们称之为 A）。这个视图控制器打开一个导航控制器作为一个模态，它通过 3 个不同的视图控制器（我们称之为 1、2 和 3）。在查看第 3 号之后，navigationcontroller 关闭，我们又回到了 A。
所以流程是：A打开navigationcontroller并经过1->2->3然后再次关闭。
每次我经历这个流程时，我都会失去记忆。为了解决这个问题，我搜索了所有文件，寻找任何保留 og 强属性、未失效的计时器或类似的东西。
我有一个想法，这可能是问题所在。在 viewcontroller 1 我使用 coreanimation 和 sprite 呈现动画。我正在使用其他人制作的实现。似乎如果我禁用动画，使用的内存似乎相当稳定（因此不会丢失内存）。我已经稍微修改了实现以使用 ARC。这是我用于精灵动画的实现：
MCSpriteLayer.h
//
// MCSpriteLayer.h
//
// Created by Miguel Angel Friginal on 8/20/10.
// Copyright 2010 Mystery Coconut Games. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <QuartzCore/QuartzCore.h>
@interface MCSpriteLayer : CALayer {
unsigned int sampleIndex;
}
// SampleIndex needs to be > 0
@property (nonatomic) unsigned int sampleIndex;
// For use with sample rects set by the delegate
+ (id)layerWithImage:(CGImageRef)img;
- (id)initWithImage:(CGImageRef)img;
// If all samples are the same size
+ (id)layerWithImage:(CGImageRef)img sampleSize:(CGSize)size :(int)useRetina;
- (id)initWithImage:(CGImageRef)img sampleSize:(CGSize)size;
// Use this method instead of sprite.sampleIndex to obtain the index currently displayed on screen
- (unsigned int)currentSampleIndex;
@end
MCSpriteLayer.m
//
// MCSpriteLayer.m
//
// Created by Miguel Angel Friginal on 8/20/10.
// Copyright 2010 Mystery Coconut Games. All rights reserved.
//
#import "MCSpriteLayer.h"
@implementation MCSpriteLayer
@synthesize sampleIndex;
#pragma mark -
#pragma mark Initialization, variable sample size
- (id)initWithImage:(CGImageRef)img;
{
self = [super init];
if (self != nil)
{
self.contents = (__bridge id)img;
sampleIndex = 1;
}
return self;
}
+ (id)layerWithImage:(CGImageRef)img;
{
MCSpriteLayer *layer = [(MCSpriteLayer*)[self alloc] initWithImage:img];
return layer;
}
#pragma mark -
#pragma mark Initialization, fixed sample size
- (id)initWithImage:(CGImageRef)img sampleSize:(CGSize)size;
{
self = [self initWithImage:img];
if (self != nil)
{
CGSize sampleSizeNormalized = CGSizeMake(size.width/CGImageGetWidth(img), size.height/CGImageGetHeight(img));
self.bounds = CGRectMake( 0, 0, size.width, size.height );
self.contentsRect = CGRectMake( 0, 0, sampleSizeNormalized.width, sampleSizeNormalized.height );
}
return self;
}
+ (id)layerWithImage:(CGImageRef)img sampleSize:(CGSize)size :(int)useRetina;
{
CGSize newSampleSize;
if(useRetina == 1) {
// Supporting retina displays
if ([[UIScreen mainScreen] respondsToSelector:@selector(displayLinkWithTarget:selector:)] &&
([UIScreen mainScreen].scale == 2.0)) {
newSampleSize = CGSizeMake(size.width*2, size.height*2);
} else {
newSampleSize = size;
}
} else
newSampleSize = size;
MCSpriteLayer *layer = [[self alloc] initWithImage:img sampleSize:newSampleSize];
return layer;
}
#pragma mark -
#pragma mark Frame by frame animation
+ (BOOL)needsDisplayForKey:(NSString *)key;
{
return [key isEqualToString:@"sampleIndex"];
}
// contentsRect or bounds changes are not animated
+ (id < CAAction >)defaultActionForKey:(NSString *)aKey;
{
if ([aKey isEqualToString:@"contentsRect"] || [aKey isEqualToString:@"bounds"])
return (id < CAAction >)[NSNull null];
return [super defaultActionForKey:aKey];
}
- (unsigned int)currentSampleIndex;
{
return ((MCSpriteLayer*)[self presentationLayer]).sampleIndex;
}
// Implement displayLayer: on the delegate to override how sample rectangles are calculated; remember to use currentSampleIndex, ignore sampleIndex == 0, and set the layer's bounds
- (void)display;
{
if ([self.delegate respondsToSelector:@selector(displayLayer:)])
{
[self.delegate displayLayer:self];
return;
}
unsigned int currentSampleIndex = [self currentSampleIndex];
if (!currentSampleIndex)
return;
CGSize sampleSize = self.contentsRect.size;
self.contentsRect = CGRectMake(
((currentSampleIndex - 1) % (int)(1/sampleSize.width)) * sampleSize.width,
((currentSampleIndex - 1) / (int)(1/sampleSize.width)) * sampleSize.height,
sampleSize.width, sampleSize.height
);
}
@end
这个实现是否以某种方式无法正确实现或保留任何东西？提前致谢。
更新 - 我正在使用仪器来测量内存。我正在使用内存监视器，我在其中密切关注物理内存可用 - 图像是这样创建的：
NSString *path = [[NSBundle mainBundle] pathForResource:@"round_start.png" ofType:nil];
CGSize fixedSize = CGSizeMake(320, 480);
mascot = [MCSpriteLayer layerWithImage:[UIImage imageWithContentsOfFile:path].CGImage sampleSize:fixedSize :0];
mascot.frame = CGRectMake(ANIMATION_X, ANIMATION_Y, ANIMATION_WIDTH, ANIMATION_HEIGHT);
[self.view.layer addSublayer:mascot2];
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"sampleIndex"];
anim.delegate = self;
anim.fromValue = [NSNumber numberWithInt:1];
anim.toValue = [NSNumber numberWithInt:52];
anim.duration = ANIMATION_DURATION;
anim.repeatCount = 1;
[mascot addAnimation:anim forKey:nil];
- 我一直在经历关闭模式
[self dismissModalViewControllerAnimated:YES];
和
[self.navigationController dismissModalViewControllerAnimated:YES];