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。
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。
下面是一种在Swift中实现的方法(目前正在XCode 7 beta 5中编写Swift 2.0)。
从你在接口构建器中设置为“自定义类”的UIView子类中创建一个像这样的方法(我的子类叫做RecordingFooterView):
class func loadFromNib() -> RecordingFooterView? {
let nib = UINib(nibName: "RecordingFooterView", bundle: nil)
let nibObjects = nib.instantiateWithOwner(nil, options: nil)
if nibObjects.count > 0 {
let topObject = nibObjects[0]
return topObject as? RecordingFooterView
}
return nil
}
然后你可以像这样调用它:
let recordingFooterView = recordingFooterView . loadfromnib ()
我不确定一些答案在谈论什么，但我需要把这个答案放在这里，当我下次在谷歌中搜索时。关键词:“如何从一个nib加载一个UIView”或“如何从一个NSBundle加载一个UIView”
下面的代码几乎100%直接来自Apress Beginning iPhone 3的书籍(第247页，“使用新的表视图单元格”):
- (void)viewDidLoad {
[super viewDidLoad];
NSArray *bundle = [[NSBundle mainBundle] loadNibNamed:@"Blah"
owner:self options:nil];
Blah *blah;
for (id object in bundle) {
if ([object isKindOfClass:[Blah class]]) {
blah = (Blah *)object;
break;
}
}
assert(blah != nil && "blah can't be nil");
[self.view addSubview: blah];
}
这假设你有一个UIView子类叫Blah，一个nib叫Blah它包含一个UIView它的类设置为Blah。
类别:+ LoadFromNib NSObject
#import "NSObject+LoadFromNib.h"
@implementation NSObject (LoadFromNib)
+ (id)loadFromNib:(NSString *)name classToLoad:(Class)classToLoad {
NSArray *bundle = [[NSBundle mainBundle] loadNibNamed:name owner:self options:nil];
for (id object in bundle) {
if ([object isKindOfClass:classToLoad]) {
return object;
}
}
return nil;
}
@end
迅速扩展
extension UIView {
class func loadFromNib<T>(withName nibName: String) -> T? {
let nib = UINib.init(nibName: nibName, bundle: nil)
let nibObjects = nib.instantiate(withOwner: nil, options: nil)
for object in nibObjects {
if let result = object as? T {
return result
}
}
return nil
}
}
还有一个正在使用的例子:
class SomeView: UIView {
class func loadFromNib() -> SomeView? {
return self.loadFromNib(withName: "SomeView")
}
}
