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
Swift用户可设计选项:
Create a custom UIView subclass and a xib files, that we will name after our own class name: in our case MemeView. Inside the Meme View class remember to define it as designable with the @IBDesignable attribute before the class declaration
Rember to set the File’s Owner in the xib with our custom UIView subclass in Indetity Inspector panel
In the xib file now we can build our interface, make constraints, create outlets, actions etc.
We need to implement few methods to our custom class to open the xib once initialized
class XibbedView: UIView {
weak var nibView: UIView!
override convenience init(frame: CGRect) {
let nibName = NSStringFromClass(self.dynamicType).componentsSeparatedByString(".").last!
self.init(nibName: nibName)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
let nibName = NSStringFromClass(self.dynamicType).componentsSeparatedByString(".").last!
let nib = loadNib(nibName)
nib.frame = bounds
nib.translatesAutoresizingMaskIntoConstraints = false
addSubview(nib)
nibView = nib
setUpConstraints()
}
init(nibName: String) {
super.init(frame: CGRectZero)
let nibName = NSStringFromClass(self.dynamicType).componentsSeparatedByString(".").last!
let nib = loadNib(nibName)
nib.frame = bounds
nib.translatesAutoresizingMaskIntoConstraints = false
addSubview(nib)
nibView = nib
setUpConstraints()
}
func setUpConstraints() {
["V","H"].forEach { (quote) -> () in
let format = String(format:"\(quote):|[nibView]|")
addConstraints(NSLayoutConstraint.constraintsWithVisualFormat(format, options: [], metrics: nil, views: ["nibView" : nibView]))
}
}
func loadNib(name: String) -> UIView {
let bundle = NSBundle(forClass: self.dynamicType)
let nib = UINib(nibName: name, bundle: bundle)
let view = nib.instantiateWithOwner(self, options: nil)[0] as! UIView
return view
}
}
In our custom class we can also define some inspecatable properties to have full control over them from interface builder
@IBDesignable
class MemeView: XibbedView {
@IBInspectable var memeImage: UIImage = UIImage() {
didSet {
imageView.image = memeImage
}
}
@IBInspectable var textColor: UIColor = UIColor.whiteColor() {
didSet {
label.textColor = textColor
}
}
@IBInspectable var text: String = "" {
didSet {
label.text = text
}
}
@IBInspectable var roundedCorners: Bool = false {
didSet {
if roundedCorners {
layer.cornerRadius = 20.0
clipsToBounds = true
}
else {
layer.cornerRadius = 0.0
clipsToBounds = false
}
}
}
@IBOutlet weak var label: UILabel!
@IBOutlet weak var imageView: UIImageView!
}
一些例子:
如果我们需要在一个故事板或另一个xib中显示视图时添加更多信息，为此我们可以实现prepareForInterfaceBuilder()，此方法仅在接口生成器中打开文件时执行。
如果你做了我写的所有事情，但没有任何工作，这是一种通过在实现中添加断点来调试单个视图的方法。
这是视图层次结构。
希望这对您有所帮助，完整的示例可以在这里下载
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 ()
