我试着做一些复杂的事情,但应该是可能的。所以这里有一个对你们所有专家的挑战(这个论坛是由你们很多人组成的:))。
我正在创建一个问卷“组件”,我想加载在一个navigationcontroller(我的QuestionManagerViewController)。“组件”是一个“空的”UIViewController,它可以根据需要回答的问题加载不同的视图。
我的做法是:
Create Question1View object as a UIView subclass, defining some IBOutlets.
Create (using Interface Builder) the Question1View.xib (HERE IS WHERE MY PROBLEM PROBABLY IS). I set both the UIViewController and the UIView to be of class Question1View.
I link the outlets with the view's component (using IB).
I override the initWithNib of my QuestionManagerViewController to look like this:
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:@"Question1View" bundle:nibBundleOrNil]) {
// Custom initialization
}
return self;
}
当我运行代码时,我得到这个错误:
2009-05-14 15:05:37.152 iMobiDines[17148:20b] ***由于未捕获异常'NSInternalInconsistencyException'而终止应用程序,原因:'-[UIViewController _loadViewFromNibNamed:bundle:] loaded the "Question1View" nib but the view outlet was not set.'
我确信有一种方法可以使用nib文件加载视图,而不需要创建一个viewController类。
花了好几个小时后,我想出了以下解决办法。
按照以下步骤创建自定义UIView。
1)创建类myCustomView继承自UIView。
2)创建名称为myCustomView的.xib。
3)在你的.xib文件中改变UIView的类,在那里分配myCustomView类。
4)创建iboutlet
5)在myCustomView * customView中加载.xib。
使用下面的示例代码。
myCustomView * myView = [[[NSBundle mainBundle] loadNibNamed:@"myCustomView" owner:self options:nil] objectAtIndex:0];
[myView.description setText:@"description"];
注:对于那些仍然面临问题的人可以评论,我将提供他们的链接
示例项目的myCustomView
我也想做一些类似的事情,这是我发现的:
(SDK 3.1.3)
我有一个视图控制器a(本身由一个导航控制器拥有),它在一个按钮按下加载VC B:
在AViewController.m
BViewController *bController = [[BViewController alloc] initWithNibName:@"Bnib" bundle:nil];
[self.navigationController pushViewController:bController animated:YES];
[bController release];
现在VC B有它的接口从Bnib,但当一个按钮被按下,我想去一个“编辑模式”有一个独立的UI从不同的nib,但我不想要一个新的VC的编辑模式,我想新的nib与我现有的B VC相关联。
在BViewController中。M(按按钮方式)
NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:@"EditMode" owner:self options:nil];
UIView *theEditView = [nibObjects objectAtIndex:0];
self.editView = theEditView;
[self.view addSubview:theEditView];
然后按下另一个按钮(退出编辑模式):
[editView removeFromSuperview];
我又变回了原来的Bnib
这很好,但请注意我的EditMode。nib中只有一个顶级obj,一个UIView obj。
不管这个nib中的文件所有者是设置为BViewController还是默认的NSObject,但要确保文件所有者中的视图出口没有设置为任何东西。
如果是,那么我得到一个exc_bad_access崩溃,xcode继续加载6677个堆栈帧
显示一个内部UIView方法被反复调用…看起来像一个无限循环。
(视图出口是设置在我原来的Bnib然而)
希望这能有所帮助。
你不应该在Interface Builder中将视图控制器的类设置为UIView的子类。这肯定是你的部分问题。保留它为UIViewController,它的子类,或者其他自定义类。
As for loading only a view from a xib, I was under the assumption that you had to have some sort of view controller (even if it doesn't extend UIViewController, which may be too heavyweight for your needs) set as the File's Owner in Interface Builder if you want to use it to define your interface. I did a little research to confirm this as well. This is because otherwise there would be no way to access any of the interface elements in the UIView, nor would there be a way to have your own methods in code be triggered by events.
If you use a UIViewController as your File's Owner for your views, you can just use initWithNibName:bundle: to load it and get the view controller object back. In IB, make sure you set the view outlet to the view with your interface in the xib. If you use some other type of object as your File's Owner, you'll need to use NSBundle's loadNibNamed:owner:options: method to load the nib, passing an instance of File's Owner to the method. All its properties will be set properly according to the outlets you define in IB.
谢谢大家。
我确实找到了做我想做的事的方法。
Create your UIView with the IBOutlets you need.
Create the xib in IB, design it to you liking and link it like this: The File's Owner is of class UIViewController (No custom subclass, but the "real" one). The File Owner's view is connected to the main view and its class is declared as the one from step 1).
Connect your controls with the IBOutlets.
The DynamicViewController can run its logic to decide what view/xib to load. Once its made the decission, in the loadView method put something like this:
NSArray* nibViews = [[NSBundle mainBundle] loadNibNamed:@"QPickOneView"
owner:self
options:nil];
QPickOneView* myView = [ nibViews objectAtIndex: 1];
myView.question = question;
就是这样!
主bundle的loadNibNamed方法将负责初始化视图和创建连接。
现在ViewController可以根据内存中的数据显示一个视图或另一个视图,而“父”屏幕不需要为这个逻辑而烦恼。
在Swift 4中以编程方式从nib/xib加载视图:
// Load a view from a Nib given a placeholder view subclass
// Placeholder is an instance of the view to load. Placeholder is discarded.
// If no name is provided, the Nib name is the same as the subclass type name
//
public func loadViewFromNib<T>(placeholder placeholderView: T, name givenNibName: String? = nil) -> T {
let nib = loadNib(givenNibName, placeholder: placeholderView)
return instantiateView(fromNib: nib, placeholder: placeholderView)
}
// Step 1: Returns a Nib
//
public func loadNib<T>(_ givenNibName: String? = nil, placeholder placeholderView: T) -> UINib {
//1. Load and unarchive nib file
let nibName = givenNibName ?? String(describing: type(of: placeholderView))
let nib = UINib(nibName: nibName, bundle: Bundle.main)
return nib
}
// Step 2: Instantiate a view given a nib
//
public func instantiateView<T>(fromNib nib: UINib, placeholder placeholderView: T) -> T {
//1. Get top level objects
let topLevelObjects = nib.instantiate(withOwner: placeholderView, options: nil)
//2. Have at least one top level object
guard let firstObject = topLevelObjects.first else {
fatalError("\(#function): no top level objects in nib")
}
//3. Return instantiated view, placeholderView is not used
let instantiatedView = firstObject as! T
return instantiatedView
}