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。


当前回答

@AVeryDev

6)将加载的视图附加到视图控制器的视图:

[self.view addSubview:myViewFromNib];

据推测,有必要将其从视图中删除以避免内存泄漏。

澄清一下:视图控制器有几个iboutlet,其中一些连接到原始nib文件中的项(像往常一样),一些连接到加载的nib中的项。两个nib都有相同的所有者类。加载的视图覆盖了原始视图。

提示:在加载的笔尖中设置主视图的不透明度为零,那么它将不会从原始笔尖中模糊项目。

其他回答

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
}

前面的答案没有考虑iPhone SDK 2.0到2.1之间发生的NIB (XIB)结构的变化。用户内容现在从索引0开始,而不是1。

你可以使用2.1宏,它适用于所有2.1及以上版本(在IPHONE前面加两个下划线):

 // Cited from previous example
 NSArray* nibViews =  [[NSBundle mainBundle] loadNibNamed:@"QPickOneView" owner:self options:nil];
 int startIndex;
 #ifdef __IPHONE_2_1
 startIndex = 0;
 #else
 startIndex = 1;
 #endif
 QPickOneView* myView = [ nibViews objectAtIndex: startIndex];
 myView.question = question;

我们在大多数应用程序中都使用类似的技术。

巴尼

我将使用UINib实例化一个自定义的UIView被重用

UINib *customNib = [UINib nibWithNibName:@"MyCustomView" bundle:nil];
MyCustomViewClass *customView = [[customNib instantiateWithOwner:self options:nil] objectAtIndex:0];
[self.view addSubview:customView];

本例中需要的文件是MyCustomView。mycustomviewclass . xib、MyCustomViewClass.h和MyCustomViewClass.m 注意,[UINib instantiatewiowner]返回一个数组,所以你应该使用反映你想要重用的UIView的元素。在这个例子中,它是第一个元素。