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。
我做了一个我喜欢的分类:
UIView + NibInitializer.h
#import <UIKit/UIKit.h>
@interface UIView (NibInitializer)
- (instancetype)initWithNibNamed:(NSString *)nibNameOrNil;
@end
UIView + NibInitializer.m
#import "UIView+NibInitializer.h"
@implementation UIView (NibInitializer)
- (instancetype)initWithNibNamed:(NSString *)nibNameOrNil
{
if (!nibNameOrNil) {
nibNameOrNil = NSStringFromClass([self class]);
}
NSArray *viewsInNib = [[NSBundle mainBundle] loadNibNamed:nibNameOrNil
owner:self
options:nil];
for (id view in viewsInNib) {
if ([view isKindOfClass:[self class]]) {
self = view;
break;
}
}
return self;
}
@end
然后，像这样调用:
MyCustomView *myCustomView = [[MyCustomView alloc] initWithNibNamed:nil];
如果你的nib不是你的类名，请使用一个nib名。
为了在你的子类中覆盖它以获得额外的行为，它可以看起来像这样:
- (instancetype)initWithNibNamed:(NSString *)nibNameOrNil
{
self = [super initWithNibNamed:nibNameOrNil];
if (self) {
self.layer.cornerRadius = CGRectGetHeight(self.bounds) / 2.0;
}
return self;
}
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 ()
对于那些需要管理多个自定义视图实例的人，也就是Outlet Collection，我合并并定制了@Gonso， @AVeryDev和@Olie的答案:
Create a custom MyView : UIView and set it as "Custom Class" of the root UIView in the desired XIB;
Create all outlets you need in MyView (do it now because after point 3 the IB will propose you to connect outlets to the UIViewController and not to the custom view as we want);
Set your UIViewController as "File's Owner" of the custom view XIB;
In the UIViewController add a new UIViews for each instance of MyView you want, and connect them to UIViewController creating an Outlet Collection: these views will act as "wrapper" views for the custom view instances;
Finally, in the viewDidLoad of your UIViewController add the following lines:
NSArray *bundleObjects;
MyView *currView;
NSMutableArray *myViews = [NSMutableArray arrayWithCapacity:myWrapperViews.count];
for (UIView *currWrapperView in myWrapperViews) {
bundleObjects = [[NSBundle mainBundle] loadNibNamed:@"MyView" owner:self options:nil];
for (id object in bundleObjects) {
if ([object isKindOfClass:[MyView class]]){
currView = (MyView *)object;
break;
}
}
[currView.myLabel setText:@"myText"];
[currView.myButton setTitle:@"myTitle" forState:UIControlStateNormal];
//...
[currWrapperView addSubview:currView];
[myViews addObject:currView];
}
//self.myViews = myViews; if need to access them later..
