Question

我想以某种方式组织我的iPhone游戏的级别视图，但我根本不能（没有扩展Object Allocations ）。我为我的代码制作了一个非常“骨架”（这个游戏有2个级别，目标是发布iPhone显示）。我只是无法释放前一级别，因此Instrunments显示增加BGTangramLevel实例。

请看一下，我需要一些有用的设计想法（我的第三个问题）。

viewcontroller.h

@interface compactTangramViewController : UIViewController
{
    //The level.
    BGTangramLevel *currentLevel;
    UIColor *levelColor;
}

//It is to be just a reference, therefore I use assign here.
@property (nonatomic, retain) BGTangramLevel *currentLevel;

-(void) notificationHandler: (NSNotification*) notification;
-(void) finishedCurrentLevel;

@end

viewcontroller.m

@implementation compactTangramViewController
@synthesize currentLevel;

//Initializer functions, setting up view hierarchy.
-(void) viewDidLoad
{   

    //Set up levelstepper.
    levelColor = [UIColor greenColor];

    //Set up "state" classes.
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(notificationHandler:) name:@"finishedCurrentLevel" object:nil];   

    //Attach level 1.
    currentLevel = [BGTangramLevel levelWithColor: levelColor frame:self.view.frame];
    [self.view addSubview:currentLevel];

    [super viewDidLoad];

}

//Release objects.
-(void) dealloc
{
    [currentLevel release];
    [super dealloc];
}

//Notification handling.
-(void) notificationHandler: (NSNotification*) notification
{
    //Execute level swap.
    if ([notification name] == @"finishedCurrentLevel") [self finishedCurrentLevel];
}

-(void) finishedCurrentLevel
{
    //Remove previous level.
    [currentLevel removeFromSuperview];
    //[currentLevel release];

    //Step level.
    if (levelColor == [UIColor greenColor]) levelColor = [UIColor blueColor]; else levelColor = [UIColor greenColor];

    //Attach level 2.
    currentLevel = [BGTangramLevel levelWithColor: levelColor frame:self.view.frame];
    [self.view addSubview:currentLevel];

}
@end

BGTangramLevel.h

@interface BGTangramLevel : UIView
{
    BOOL puzzleCompleted;   
}

//Initializer.
+(BGTangramLevel*)levelWithColor: (UIColor*) color frame: (CGRect) frame;

//Test if the puzzle is completed.
-(void) isSolved;

@end

BGTangramLevel.m

@implementation BGTangramLevel

//Allocated instance.
+(BGTangramLevel*)levelWithColor: (UIColor*) color frame: (CGRect) frame
{
    BGTangramLevel *allocatedLevel = [[BGTangramLevel alloc] initWithFrame:frame];
    allocatedLevel.backgroundColor = color;
    return allocatedLevel;
}

//Finger released.
-(void) touchesEnded: (NSSet*)touches withEvent: (UIEvent*)event
{
    //The completement condition is a simple released tap for now...
    puzzleCompleted = YES;
    [self isSolved];    
}

//Test if the puzzle is completed.
-(void) isSolved
{
    //"Notify" viewController if puzzle has solved.
    if (puzzleCompleted) [[NSNotificationCenter defaultCenter] postNotificationName:@"finishedCurrentLevel" object:nil]; 
}

-(void) dealloc
{
    NSLog(@"Will ever level dealloc invoked."); //It is not.
    [super dealloc];
}

@end

那我该怎么办？我试图标记自动释放返回的级别实例，在removeFromSuperview之后释放currentLevel，尝试以（非原子，assign）方式合成的currentLevel属性，但是Object Allocations仍然增长。我可以避免通知吗？我被卡住了。

Answer 1

您需要更密切地遵循保留/发布规则。你绝对不应该在实验中添加保留，释放和自动释放，只是为了找到有用的东西。已经有很多关于Cocoa内存管理的文章，我在此不再重复。

具体来说，BGTangramLevel的levelWithColor:frame:方法应该在将allocatedLevel返回给调用者之前调用[allocatedLevel autorelease]。它不拥有该对象，由调用者保留它。

您还需要了解访问实例变量和访问属性之间的区别。 Cocoa的属性只是getter和setter方法的语法糖。在视图控制器中引用currentLevel时，您将直接处理实例变量。当您引用self.currentLevel时，您正在处理该财产。

即使您已声明属性，currentLevel = [BGTangram ...]也只是将引用复制到变量中。在viewDidLoad中，如果要查看属性的setter方法，则需要使用self.currentLevel = [BGTangram ...]，该方法将保留对象（因为您以此方式声明了属性）。看到区别？

我认为您的泄密发生在finishedCurrentLevel。如果您使用过self.currentLevel = [BGTangram ...]，则会调用属性的setter方法，该方法将释放旧对象并保留新对象。因为您直接分配给实例变量，所以只需覆盖旧级别的引用而不释放它。

在视图控制器的[currentLevel release]方法中调用dealloc是正确的。

“交换”UIView实例变量 - 无法取消“先前”视图

1 个答案: