UIViewController不保留其以编程方式创建的UISearchDisplayController [英] UIViewController does not retain its programmatically-created UISearchDisplayController

问题描述

在 UIViewController 文档关于 searchDisplayController 属性 1 它说：

如果以编程方式创建搜索显示控制器，搜索显示控制器在初始化时会自动设置此属性。

If you create your search display controller programmatically, this property is set automatically by the search display controller when it is initialized.

当我这样创建我的UISearchDisplayController时：

And when I create my UISearchDisplayController thusly:

[[[UISearchDisplayController alloc] initWithSearchBar:searchBar contentsController:self] autorelease];

- [UIViewController searchDisplayController] 不是零。但是，它在事件循环结束后被填零，这会导致搜索显示控制器在我在搜索栏内部触摸时不显示。什么都没有崩溃。这很奇怪。如果我省略对 autorelease 的调用，一切正常：

-[UIViewController searchDisplayController] is not nil. However, it is nilled out after the event loop finishes, which causes the search display controller not to show when I touch inside the search bar. Nothing crashes. This is very weird. If I omit the call to autorelease, everything works:

[[UISearchDisplayController alloc] initWithSearchBar:searchBar contentsController:self];

然而，泄漏了 UISearchDisplayController （我验证了）这与仪器）。由于 searchDisplayController property 被标记为（nonatomic，retain，readonly）我希望它将在设置后保留 UISearchDisplayController 。

However, leaks the UISearchDisplayController (I verified this with Instruments). Since the searchDisplayController property is marked as (nonatomic, retain, readonly) I expect that it would retain the UISearchDisplayController after it is set.

此stackoverflow文章是相关的。

推荐答案

我遇到了同样的问题。事情。我以编程方式创建所有控制器/视图。一切都工作正常，直到我转换我的项目使用ARC。一旦我做了 UISearchDisplayControllers 不再保留，并且每个 UIViewController中的 searchDisplayController 属性为零。

I've run into the same thing. I create all of my controllers/views programmatically. Everything was working fine until I converted my project to use ARC. Once I did the UISearchDisplayControllers were no longer retained and the searchDisplayController property in each UIViewController was nil after the run loop ended.

我没有回答为什么会这样。 Apple文档建议SDC应该由视图控制器保留，但这显然不会发生。

I don't have an answer why this is happening. The Apple docs suggest that the SDC should be retained by the view controller but this is clearly not happening.

我的解决方案是创建第二个属性来保留SDC和我当我卸载视图时没有。如果您不使用ARC，则需要在 viewDidUnload 和 dealloc mySearchDisplayController C $ C>。否则这很好。

My solution was to create a second property to retain the SDC and I nil it when I unload the view. If you are not using ARC you need to release mySearchDisplayController in viewDidUnload and dealloc. Otherwise this is good as is.

在MyViewController.h中：

In MyViewController.h:

@property (nonatomic, strong) UISearchDisplayController * mySearchDisplayController;

在MyViewController.m中：

In MyViewController.m:

@synthesize mySearchDisplayController = _mySearchDisplayController;

- (void)viewDidLoad
{
    [super viewDidLoad];
    // create searchBar
    _mySearchDisplayController = [[UISearchDisplayController alloc] initWithSearchBar:searchBar contentsController:self];
    _mySearchDisplayController.delegate = self;
    _mySearchDisplayController.searchResultsDataSource = self;
    _mySearchDisplayController.searchResultsDelegate = self;
    // other stuff
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    _mySearchDisplayController = nil;
    // other stuff
}

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