我有一个Objective-C UIView类: ChoosePersonView.h @class Person;@interface ChoosePersonView : MDCSwipeToChooseView@property (nonatomic, strong, readonly) Person *person;- (instancetype)initWithFrame:(CGRect)frame person:(Person *)pers
ChoosePersonView.h
@class Person; @interface ChoosePersonView : MDCSwipeToChooseView @property (nonatomic, strong, readonly) Person *person; - (instancetype)initWithFrame:(CGRect)frame person:(Person *)person options:(MDCSwipeToChooseViewOptions *)options; @end
MDCSwipeToChooseView.m
@class MDCSwipeToChooseViewOptions; @interface MDCSwipeToChooseView : UIView @property (nonatomic, strong) UIImageView *imageView; @property (nonatomic, strong) UIView *likedView; @property (nonatomic, strong) UIView *nopeView; - (instancetype)initWithFrame:(CGRect)frame options:(MDCSwipeToChooseViewOptions *)options; @end
通常我会子类化并使用它如下:
ChoosePersonView.m
@implementation ChoosePersonView #pragma mark - Object Lifecycle - (instancetype)initWithFrame:(CGRect)frame person:(Person *)person options:(MDCSwipeToChooseViewOptions *)options { self = [super initWithFrame:frame options:options]; if (self) { _person = person; self.imageView.image = _person.image; self.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin; self.imageView.autoresizingMask = self.autoresizingMask; [self constructInformationView]; } return self; } ... @end
我面临的问题是当我尝试在Swift中执行此操作时,属性self.imageView始终为nil.
我不确定如何重新实现initWithFrame,因为它在Swift中的Objective-C中实现.我认为使用init(frame:CGRect,person:Person,options:MDCSwipeToChooseViewOptions)是正确的方法,但我想我可能是错的.
ChoosePersonView.swift
class ChoosePersonView: MDCSwipeToChooseView { var informationView: UIView! var nameLabel: UILabel! var cameraImageLabelView: ImageLabelView! var interestsImageLabelView: ImageLabelView! var friendsImageLabelView: ImageLabelView! var person: Person! let ChoosePersonViewImageLabelWidth = CGFloat(42.0) // #pragma mark - Object Lifecycle init(frame: CGRect, person: Person, options: MDCSwipeToChooseViewOptions) { super.init(frame: frame) self.person = person self.imageView.image = self.person.image // self.imageView is nil. self.autoresizingMask = .FlexibleHeight | .FlexibleWidth | .FlexibleBottomMargin self.imageView.autoresizingMask = self.autoresizingMask self.constructInformationView() } .... }self.imageView是零,因为你没有做任何事情使它不是零.你没有显示任何会使它不是零的代码,所以你很难想象你应该怎么想.
我的猜测是,它是MDCSwipeToChooseView的初始化程序的工作,您可以将其称为super.init(frame:options :),以创建imageView.很难说,因为你没有显示代码.当然,这是在Objective-C中编写ChoosePersonView时调用的初始化程序.那么为什么你现在也没有调用它,现在它是用Swift编写的?出于某种原因,您选择不调用该初始化程序 – 您正在调用super.init(frame :).这似乎是一件非常奇怪的事情.也许这就是你出错的地方.
但无论如何,我可以向你保证,如果你不调用一些导致imageView不为nil的代码,它将是nil,因为这是Objective-C中所有对象属性的默认值.