释放一个需要大量内存的弹出窗口

Question

我正在使用一个弹出式视图来呈现大量的旗帜，您可以从中选择。我的代码有问题，因为在我打开这个弹出窗口后不久，内存没有被释放(视图控制器"flagsViewController“是正常的和干净的，它初始化并释放它里面的每一项。

我做错了什么？如何在关闭弹出窗口后立即释放内存？

    -(void)presentFlags
    {
        [self.popoverController dismissPopoverAnimated:YES];

        FlagsViewController *controller = [[FlagsViewController alloc] 
                                            initWithNibName:@"FlagsViewController" 
                                            bundle:[NSBundle mainBundle]] ;

        UINavigationController *container = [[UINavigationController alloc] initWithRootViewController:controller];

        UISegmentedControl *ctrl = [[UISegmentedControl alloc] initWithItems:segmentedItems];
        ctrl.frame = CGRectMake(0, 6, 500, 30);
        [ctrl addTarget:self action:@selector(changeSeg:) forControlEvents:UIControlEventValueChanged];
        ctrl.segmentedControlStyle = UISegmentedControlStyleBar;
        //ctrl.momentary = YES; 
        ctrl.tintColor  = [UIColor darkGrayColor];
        UIImage *theImage = [UIImage imageNamed:@"highlight_country.png"];

        [ctrl setImage:theImage forSegmentAtIndex:0];

        [container.navigationBar addSubview:ctrl];
        [ctrl release];
        //
        //create a popover controller
        self.popoverController = [[[UIPopoverController alloc]
                                   initWithContentViewController:container] autorelease];
        [container  release];
        [popoverController setPopoverContentSize:CGSizeMake(500, 600)];
        //present the popover view non-modal with a
        //refrence to the button pressed within the current view
        [popoverController presentPopoverFromRect:CGRectMake(popoverArrowPossition, 0.0, 0.0, 52.0) inView:super.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
        [controller release];
}

Answer 1

使用UIPopoverController非常困难，但我通过执行以下操作解决了这个问题:将Popover Controller的委派设置为self (popoverController.delegate = self)并将UIPopoverControllerDelegate协议添加到您的类头

接下来，我实现了- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController委托方法，在这里我释放了popoverController并将其设置为nil。

- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController {
    [self.popoverController release];
    self.popoverController = nil;
}

请注意:如果您通过代码(即使用dismissPopoverAnimated)关闭弹出窗口，则不会调用此委托方法，只有当此用户通过在弹出窗口外点击来取消弹出窗口时才会调用它。