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")
}
}
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..
我也想做一些类似的事情，这是我发现的:
(SDK 3.1.3)
我有一个视图控制器a(本身由一个导航控制器拥有)，它在一个按钮按下加载VC B:
在AViewController.m
BViewController *bController = [[BViewController alloc] initWithNibName:@"Bnib" bundle:nil];
[self.navigationController pushViewController:bController animated:YES];
[bController release];
现在VC B有它的接口从Bnib，但当一个按钮被按下，我想去一个“编辑模式”有一个独立的UI从不同的nib，但我不想要一个新的VC的编辑模式，我想新的nib与我现有的B VC相关联。
在BViewController中。M(按按钮方式)
NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:@"EditMode" owner:self options:nil];
UIView *theEditView = [nibObjects objectAtIndex:0];
self.editView = theEditView;
[self.view addSubview:theEditView];
然后按下另一个按钮(退出编辑模式):
[editView removeFromSuperview];
我又变回了原来的Bnib
这很好，但请注意我的EditMode。nib中只有一个顶级obj，一个UIView obj。
不管这个nib中的文件所有者是设置为BViewController还是默认的NSObject，但要确保文件所有者中的视图出口没有设置为任何东西。
如果是，那么我得到一个exc_bad_access崩溃，xcode继续加载6677个堆栈帧
显示一个内部UIView方法被反复调用…看起来像一个无限循环。
(视图出口是设置在我原来的Bnib然而)
希望这能有所帮助。
