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。
我有一种命名xib的约定，其中的视图与视图相同。和视图控制器一样。这样，我就不必在代码中写出类名了。我从同名的nib文件中加载一个UIView。
一个名为MyView的类的例子。
创建一个名为MyView的nib文件。接口生成器中的xib
在Interface Builder中添加一个UIView。将其类设置为MyView。自定义到你的内心的内容，连接MyView的实例变量到子视图，你可能想以后访问。
在你的代码中，像这样创建一个新的MyView:
MyView * MyView = [MyView nib_viewfromnibwiowner:owner];
这是它的分类:
@implementation UIView (nib)
+ (id) nib_viewFromNib {
return [self nib_viewFromNibWithOwner:nil];
}
+ (id) nib_viewFromNibWithOwner:(id)owner {
NSString *className = NSStringFromClass([self class]);
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:className owner:owner options:nil];
UIView *view = nil;
for(UIView *v in nib) {
if ([v isKindOfClass:[self class]]) {
view = v;
break;
}
}
assert(view != nil && "View for class not found in nib file");
[view nib_viewDidLoad];
return view;
}
// override this to do custom setup
-(void)nib_viewDidLoad {
}
然后，我将连接按钮与我正在使用的控制器的动作，并使用自定义视图子类中的outlet在标签上设置内容。
我有一种命名xib的约定，其中的视图与视图相同。和视图控制器一样。这样，我就不必在代码中写出类名了。我从同名的nib文件中加载一个UIView。
一个名为MyView的类的例子。
创建一个名为MyView的nib文件。接口生成器中的xib
在Interface Builder中添加一个UIView。将其类设置为MyView。自定义到你的内心的内容，连接MyView的实例变量到子视图，你可能想以后访问。
在你的代码中，像这样创建一个新的MyView:
MyView * MyView = [MyView nib_viewfromnibwiowner:owner];
这是它的分类:
@implementation UIView (nib)
+ (id) nib_viewFromNib {
return [self nib_viewFromNibWithOwner:nil];
}
+ (id) nib_viewFromNibWithOwner:(id)owner {
NSString *className = NSStringFromClass([self class]);
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:className owner:owner options:nil];
UIView *view = nil;
for(UIView *v in nib) {
if ([v isKindOfClass:[self class]]) {
view = v;
break;
}
}
assert(view != nil && "View for class not found in nib file");
[view nib_viewDidLoad];
return view;
}
// override this to do custom setup
-(void)nib_viewDidLoad {
}
然后，我将连接按钮与我正在使用的控制器的动作，并使用自定义视图子类中的outlet在标签上设置内容。
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。
这是一个很好的问题(+1)，答案几乎是有帮助的;)抱歉，伙计们，虽然Gonso和AVeryDev都给出了很好的提示，但我花了很长时间才读完这篇文章。希望这个答案能帮助到其他人。
MyVC是持有这些东西的视图控制器。
MySubview是我们想从xib中加载的视图
In MyVC.xib, create a view of type MySubView that is the right size & shape & positioned where you want it.
In MyVC.h, have
IBOutlet MySubview *mySubView
// ...
@property (nonatomic, retain) MySubview *mySubview;
In MyVC.m, @synthesize mySubView; and don't forget to release it in dealloc.
In MySubview.h, have an outlet/property for UIView *view (may be unnecessary, but worked for me.) Synthesize & release it in .m
In MySubview.xib
set file owner type to MySubview, and link the view property to your view.
Lay out all the bits & connect to the IBOutlet's as desired
Back in MyVC.m, have
NSArray *xibviews = [[NSBundle mainBundle] loadNibNamed: @"MySubview" owner: mySubview options: NULL];
MySubview *msView = [xibviews objectAtIndex: 0];
msView.frame = mySubview.frame;
UIView *oldView = mySubview;
// Too simple: [self.view insertSubview: msView aboveSubview: mySubview];
[[mySubview superview] insertSubview: msView aboveSubview: mySubview]; // allows nesting
self.mySubview = msView;
[oldCBView removeFromSuperview];
对我来说棘手的一点是:其他答案中的提示从xib加载了我的视图，但没有替换MyVC中的视图(呸!)——我必须自己交换。
同样，为了访问mySubview的方法，.xib文件中的view属性必须设置为mySubview。否则，它会返回一个普通的UIView。
如果有一种方法来加载mySubview直接从它自己的xib，那将摇滚，但这让我在我需要的地方。
