UIPopoverController，UIActionSheet和模态视图控制器的保留/释放模式？ [英] Retain/release pattern for UIPopoverController, UIActionSheet, and modal view controllers?

问题描述

我对以下实例所需的对象所有权模式有些不清楚。当我的UIViewController将弹出控制器，操作表或其他视图控制器显示为模态时，我是否需要挂起对该子控制器的保留引用，直到它被解除为止？

I'm somewhat unclear on the object ownership patterns required for the following instances. When my UIViewController presents a popover controller, an action sheet, or another view controller as modal, am I required to hang onto a retained reference to that child controller until it's been dismissed?

换句话说，下面的代码行是否有效地转移所有权，或者没有？

In other words, do the following lines of code effectively "transfer" ownership, or not?

[aPopoverController presentPopoverFromBarButtonItem:someButtonItem permittedArrowDirections:UIPopoverArrowDirectionAny animated:NO];

[anActionSheet showFromBarButtonItem:someButtonItem animated:NO];

[aViewController presentModalViewController:someOtherViewController animated:YES];

有人能指出我有关此主题的明确文件吗？

Can someone point me to explicit documentation on this subject?

推荐答案

UIPopoverViewController有一个略微不同的内存管理/拥有。提出一个popover不会保留内存，所以你不能将你的popviewcontroller的所有权转移到呈现对象。

UIPopoverViewController has a slight different memory management/owning. Present a popover does not retain the memory, so you can't transfer the ownership of your popviewcontroller to the presenting object.

为了避免内存泄漏，你必须采用UIPopoverControllerDelegate并实现DidDismissPopOver方法如下：

To avoid memory leak, you have to adopt the UIPopoverControllerDelegate and implement the DidDismissPopOver method as follow:

- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController {
    [popoverController release];
}

这样，您可以安全地分配并呈现PopOver：

This way, you can safe alloc and present a PopOver:

-(void)showSearch:(id)sender {
    SearchViewController *searchVC = [[SearchViewController alloc] init];
    UIPopoverController *popVC = [[UIPopoverController alloc] initWithContentViewController:searchVC];
    popVC.delegate = self;
    [popVC setPopoverContentSize:CGSizeMake(320, 100)];
    [popVC presentPopoverFromRect:CGRectMake(200, 200, 320, 100) inView:self.view permittedArrowDirections:0 animated:YES];
    [searchVC release];
}

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