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。
这是一件应该比较容易的事情。我最终扩展了UIViewController并添加了一个loadNib:inPlaceholder: selector。现在我可以说
self.mySubview = (MyView *)[self loadNib:@"MyView" inPlaceholder:mySubview];
下面是这个类别的代码(它和Gonso描述的一样):
@interface UIViewController (nibSubviews)
- (UIView *)viewFromNib:(NSString *)nibName;
- (UIView *)loadNib:(NSString *)nibName inPlaceholder:(UIView *)placeholder;
@end
@implementation UIViewController (nibSubviews)
- (UIView *)viewFromNib:(NSString *)nibName
{
NSArray *xib = [[NSBundle mainBundle] loadNibNamed:nibName owner:self options:nil];
for (id view in xib) { // have to iterate; index varies
if ([view isKindOfClass:[UIView class]]) return view;
}
return nil;
}
- (UIView *)loadNib:(NSString *)nibName inPlaceholder:(UIView *)placeholder
{
UIView *nibView = [self viewFromNib:nibName];
[nibView setFrame:placeholder.frame];
[self.view insertSubview:nibView aboveSubview:placeholder];
[placeholder removeFromSuperview];
return nibView;
}
@end
我有理由做同样的事情(从XIB文件编程加载一个视图)，但我需要完全从一个UIView的子类的子类的上下文(即不涉及视图控制器的任何方式)。为了做到这一点，我创建了这个实用方法:
+ (id) initWithNibName:(NSString *)nibName withSelf:(id)myself {
NSArray *bundle = [[NSBundle mainBundle] loadNibNamed:nibName
owner:myself options:nil];
for (id object in bundle) {
if ([object isKindOfClass:[myself class]]) {
return object;
}
}
return nil;
}
然后我从我的子类的initWithFrame方法调用它，如下所示:
- (id)initWithFrame:(CGRect)frame {
self = [Utilities initWithNibName:@"XIB1" withSelf:self];
if (self) {
// Initialization code.
}
return self;
}
张贴的一般利益;如果有人发现没有这样做的问题，请告诉我。
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 ()
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。
