Question

我正在使用以下方法开发iPhone应用程序：

- (void)drawView:(ARCoordinate *)coordinate {

    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, BOX_WIDTH, 20.0)];

    [titleLabel setBackgroundColor: [UIColor colorWithWhite:.3 alpha:.8]];
    [titleLabel setTextColor:       [UIColor whiteColor]];
    [titleLabel setTextAlignment:   UITextAlignmentCenter];
    [titleLabel setText:            [coordinate title]];
    [titleLabel sizeToFit];
    [titleLabel setFrame:   CGRectMake(BOX_WIDTH / 2.0 - [titleLabel bounds].size.width / 2.0 - 4.0, 
                                       0, 
                                       [titleLabel bounds].size.width + 8.0, 
                                       [titleLabel bounds].size.height + 8.0)];

    UILabel *subTitleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, BOX_WIDTH, 20.0)];

    [subTitleLabel setBackgroundColor: [UIColor colorWithWhite:.3 alpha:.8]];
    [subTitleLabel setTextColor:        [UIColor whiteColor]];
    [subTitleLabel setTextAlignment:    UITextAlignmentCenter];
    [subTitleLabel setText:         [coordinate subtitle]];
    [subTitleLabel sizeToFit];
    [subTitleLabel setFrame: CGRectMake(BOX_WIDTH / 2.0 - [subTitleLabel bounds].size.width / 2.0 - 4.0, 
                                        21.0, 
                                        [subTitleLabel bounds].size.width + 8.0,
                                        [subTitleLabel bounds].size.height + 8.0)];

    UIImageView *pointView  = [[UIImageView alloc] initWithFrame:CGRectZero];
    [pointView setImage:    [UIImage imageNamed:@"location.png"]];
    [pointView setFrame:    CGRectMake((int)(BOX_WIDTH / 2.0 - [pointView image].size.width / 2.0),
                                       (int)(BOX_HEIGHT / 2.0 - [pointView image].size.height / 2.0),
                                       [pointView image].size.width, [pointView image].size.height)];

    [self addSubview:titleLabel];
    [self addSubview:subTitleLabel];
    [self addSubview:pointView];

    self.backgroundColor = [UIColor clearColor];
}

此代码运行良好，编译器不会抱怨它。但我不确定为什么我不必做以下事情：

[titleLabel release];
[subTitleLabel release];
[pointView release];

我认为，是由于这些视图被添加到另一个视图（此方法位于从View继承的类中）。

[self addSubview:titleLabel];
[self addSubview:subTitleLabel];
[self addSubview:pointView];

有什么建议吗？

Answer 1

为了避免内存泄漏，您应该在将这些视图添加为子视图后将其释放！

[self addSubview:titleLabel];
[self addSubview:subTitleLabel];
[self addSubview:pointView];    

[titleLabel release];
[subTitleLabel release];
[pointView release];

Answer 2

这取决于。您是否在iOS 5上使用自动引用计数执行此操作？然后你不再需要打电话了。

如果您使用的是iOS 4或不使用ARC，那么如果您不进行发布，编译器不会抱怨，但您的代码肯定会泄漏内存。

尝试通过Xcode Analyzer运行此代码，该代码应指向您。

释放添加到另一个视图的视图

2 个答案: