superview和parentviewcontroller nil添加一个子视图后 [英] superview and parentviewcontroller nil after adding a subview
问题描述
我想我缺少一些基本的东西，所以我想问社群一些帮助。我正在基于一个基本的iPhone实用程序应用程序构建一个应用程序。我的MainView和FlipsideView共享一些元素，所以我已经为这些块创建了单独的ViewControllers和nib文件。为了做到这一点，我做了以下：
1.创建一个viewcontroller名为searchDateViewController，它是searchDateView.xib的文件的所有者
2. searchDateView.xib基本上是一个UIView里面的UILabel，视图已正确连接
3.在MainViewController.m和FlipsideViewController.m内部，我添加一个子视图如下：
I think I'm missing something fundamental and so I want to ask the community for some help. I'm building an app based around a basic iPhone Utility Application. My MainView and FlipsideView share some elements so I have created separate ViewControllers and nib files for those pieces. In order to do this I have done the following: 1. Created a viewcontroller called searchDateViewController which is the file's owner of searchDateView.xib 2. searchDateView.xib is basically a UIView with a UILabel inside, the view is wired up correctly 3. Inside both MainViewController.m and FlipsideViewController.m I add a subview as folllows:
- (void)loadView{
[super loadView];
searchDateViewController = [[SearchDateViewController alloc] initWithNibName:@"SearchDateView" bundle:nil];
[[searchDateViewController view] setFrame:[searchDateView frame]];
[[self view] addSubview:[searchDateViewController view]];
...
}
精细。基本上取决于在每个主视图和双侧视图中发生的动作，改变了nib的UILabel。但是，如果searchDateViewController从MainView或FlipsideView加载，我想做一些稍微不同的事情。但是，我似乎不知道哪个ViewController添加了searchDateViewController子视图。
Everything displays and works just fine. Basically depending on actions that happen in each of the main and flipside views the UILabel of the nib is changed. However, I wanted to do something slightly different if the searchDateViewController is loaded from the MainView or the FlipsideView. However, I can't seem to figure out which ViewController is adding the searchDateViewController subview.
在searchDateViewController中我尝试：
In searchDateViewController I tried:
- (void)viewDidLoad {
[super viewDidLoad];
NSLog(@"superview %@", self.view.superview);
NSLog(@"parentviewcontroller %@", self.parentViewController);
}
在这两种情况下，我得到nil。
In both cases I get nil.
所以我的问题是 - 我可以找出哪个ViewController添加searchDateViewController aa subview？如果是这样怎么样？或者如果我的逻辑完全搞乱了，我应该怎么做呢？
So my question is - can I find out which ViewController is adding searchDateViewController a a subview? If so how? Or if my logic here is completely messed up, how should I be doing this?
谢谢！
推荐答案
viewDidLoad 。在你的case，这发生在这一行：
viewDidLoad is invoked when the view controller has loaded its view. In your case, that happends in this line:
[[searchDateViewController view] setFrame:[searchDateView frame]];
此时，您尚未调用 addSubview：
At that moment, you haven't yet called addSubview: so it is no wonder the view's superview is nil.
为了解决你的问题，你应该在SearchDateViewController中定义一个属性来区分不同的情况。这个属性将由创建SearchDateViewController实例的父控制器相应地设置。
To solve your problem, you should define a property inside SearchDateViewController to distinguish between the different cases. This property would then be set accordingly by the parent controller that creates the SearchDateViewController instance.
一般来说，我认为使用UIViewController子类不是一个好主意控制器，用作一个或多个全屏视图的子视图，而不是用作全屏视图本身。 UIViewController的大部分逻辑都是假设它用于管理全屏视图。例如，对于你的设计，我认为SearchDateViewController可能会修改视图的框架，当设备方向更改等。由于你不需要所有这个功能的非全屏子视图，我建议你直接子类化SearchDateViewController从NSObject 。
Generally, I do not think it is a good idea to use a UIViewController subclass as a controller for a view that is used as a subview of one or several fullscreen views rather than be used as a fullscreen view itself. Much of UIViewController's logic works on the assumption that it is used to manage a fullscreen view. For instance, with your design, I think it's possible that SearchDateViewController will modify the view's frame when the device orientation changes etc. Since you don't need all this functionality for a non-fullscreen subview, I suggest you subclass your SearchDateViewController directly from NSObject.
这篇关于superview和parentviewcontroller nil添加一个子视图后的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
