记忆问题

Question

是否可以检查视图控制器子类的这一部分是否存在内存泄漏。我不太擅长发现泄密。我需要这个类能够多次加载，而不会因为内存泄漏而崩溃。每次需要返回主菜单时，都会调用结束游戏。我希望它能够回到主菜单，而不留下任何内存占用。

UIImageView* questionImage;
UIImageView* questionImage2;

UIButton* questionButton1;
UIButton* questionButton2;
UIButton* questionButton3;
UIButton* questionButton4;
UIButton* questionButton5;
UIButton* questionButton6;

UIButton* achievementbutton;
UIButton* endbutton;

UILabel* questionText;
UILabel* ButtonLabel;

- (void)viewDidLoad 
{
    [super viewDidLoad];
    [self StartTimer];

    TotalSeconds = 0;
    GameCenterTotalSeconds = 0;
    timeSec = 0;
    timeMin = 0;

    Background = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 480, 320)] ;
    Background.image = [UIImage imageWithContentsOfFile:[ [ NSBundle mainBundle] pathForResource:@"Background" ofType:@"png"]];
    [self.view addSubview:Background];

    timeLabel.textColor = [UIColor redColor];
    [self.view addSubview:timeLabel];

    NumberLabel = [[UIImageView alloc] initWithFrame:CGRectMake(0, -4, 60, 70)] ;
    NumberLabel.image = [UIImage imageWithContentsOfFile:[[ NSBundle mainBundle] pathForResource:@"Number" ofType:@"png"]];
    [self.view addSubview:NumberLabel];

    QuestionNumber = [[UILabel alloc] initWithFrame:CGRectMake(23, 17, 20, 20)] ;
    QuestionNumber.text = @"1";
    QuestionNumber.textColor = [UIColor redColor];
    QuestionNumber.backgroundColor = [UIColor clearColor];
    [QuestionNumber setFont:[UIFont fontWithName:@"Marker Felt" size:30]];
    [self.view addSubview:QuestionNumber];

    numberLives = 1;

    appDelegate = (OppositeMoronTestAppDelegate *)[[UIApplication sharedApplication]delegate];

    musicButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain] ;
    musicButton.frame = CGRectMake(5, 283, 35, 35);
    musicButton.backgroundColor = [UIColor clearColor];

    if (appDelegate.shouldPlayMusic == YES) {

        UIImage *Image = [UIImage imageWithContentsOfFile:[[ NSBundle mainBundle] pathForResource:@"MusicOn" ofType:@"png"]];
        [musicButton setBackgroundImage:Image forState:UIControlStateNormal];
        [musicButton addTarget:self action:@selector(TurnMusicOff) forControlEvents:UIControlEventTouchUpInside];
    } else {
        UIImage *Image = [UIImage imageWithContentsOfFile:[[ NSBundle mainBundle] pathForResource:@"MusicOff" ofType:@"png"]];
        [musicButton setBackgroundImage:Image forState:UIControlStateNormal];
        [musicButton addTarget:self action:@selector(TurnMusicOn) forControlEvents:UIControlEventTouchUpInside];
    }

    [self.view addSubview:musicButton];
    [self showQuestion1];
}

- (void) showQuestion1 
{
    questionImage = [[UIImageView alloc] initWithFrame:CGRectMake(15, 50, 430, 270)] ;
    questionImage.image = [UIImage imageWithContentsOfFile:[[ NSBundle mainBundle] pathForResource:@"Q1new" ofType:@"png"]];
    [self.view addSubview:questionImage];

    questionButton5 = [UIButton buttonWithType:UIButtonTypeCustom];
    [questionButton5 addTarget:self action:@selector(showQuestion2Part1)forControlEvents:UIControlEventTouchDown];
    questionButton5.frame = CGRectMake(109, 75, 90, 65);
    [self.view addSubview:questionButton5];

    questionButton1 = [UIButton buttonWithType:UIButtonTypeCustom];
    [questionButton1 addTarget:self action:@selector(wronganswer)forControlEvents:UIControlEventTouchDown];
    questionButton1.frame = CGRectMake(230, 50, 120, 90);
    [self.view addSubview:questionButton1];

    questionButton2 = [UIButton buttonWithType:UIButtonTypeCustom];
    [questionButton2 addTarget:self action:@selector(wronganswer)forControlEvents:UIControlEventTouchDown];
    questionButton2.frame = CGRectMake(300, 144, 100, 90);
    [self.view addSubview:questionButton2];

    questionButton3 = [UIButton buttonWithType:UIButtonTypeCustom];
    [questionButton3 addTarget:self action:@selector(wronganswer)forControlEvents:UIControlEventTouchDown];
    questionButton3.frame = CGRectMake(203, 187, 95, 90);
    [self.view addSubview:questionButton3];

    questionButton4 = [UIButton buttonWithType:UIButtonTypeCustom];
    [questionButton4 addTarget:self action:@selector(wronganswer)forControlEvents:UIControlEventTouchDown];
    questionButton4.frame = CGRectMake(67, 140, 120, 95);
    [self.view addSubview:questionButton4];

    questionText = [[UILabel alloc] initWithFrame:CGRectMake(80, 20, 300, 30)] ;
    questionText.text = @"Press the Addition Sign";
    questionText.textColor = [UIColor blackColor];
    questionText.backgroundColor = [UIColor clearColor];
    [questionText setFont:[UIFont fontWithName:@"Marker Felt" size:30]];
    [self.view addSubview:questionText];
}
- (void) endgame 
{
    [WrongBackground release];
    [gameOver release];
    [wrongLivesLeft release];
    [questionImage release];
    [questionText release];
    [Background release];
    [NumberLabel release];
    [musicButton release];
    [questionImage release];
    [questionText release];

    [self.view removeFromSuperview];
}

Answer 1

在-viewDidLoad中有几个视图是作为子视图分配和安装的。其中包括NumberLabel、Background和QuestionNumber。(顺便说一句，如果您坚持使用Objective命名约定并使用小写字母开始变量，那么您的代码就会容易一些。)这些似乎是实例变量，但是您没有提供类声明，所以很难确定。无论如何，如果您不需要在添加到主视图之后再次引用这些视图，最好是让它们成为局部变量，而不是ivars，并立即释放它们。(一旦添加了它们，视图将保留它们。)卸载视图时，将释放所有这些子视图。

QuestionNumber不是在您提供的代码中发布的--这可能是一个漏洞。

目前还不清楚timelabel是从哪里来的，也不清楚它是否真正指向视图。

您正在发布WrongBackground，但这不是在-viewDidLoad中创建的，因此很难知道这是否正确。

像questionButton1和朋友这样的变量看起来像文件范围的全局变量，而不是实例变量，但是没有说明原因。把他们变成象牙不是有道理的吗？