从UIViewController实例化UIView子类

我发现了一个教程，该教程完全可以在我现有的Objective-C项目中完成我想做的事情，但是它是用Swift编写的。我了解Swift中的所有内容，但遇到了一个噩梦般的时光，将“UIView's初始化”转换为“ Objective-C”。这应该非常简单，但是我无法弄清楚。

我的代码不会崩溃，但是不会加载任何东西。UIViewController当我尝试加载UIView子类时，我在其中设置了一个断点，以查看发生了什么，这是我所看到的：

(lldb) po self.boxSize
75

(lldb) po self.holderView.frame
(origin = (x = 0, y = 0), size = (width = 0, height = 0))
 (origin = (x = 0, y = 0), size = (width = 0, height = 0))

(lldb) po self.holderView
 nil

这是我试图在Objective-C中“复制”的视图。

HolderView.swift：

class HolderView: UIView {

    var parentFrame :CGRect = CGRectZero

    weak var delegate:HolderViewDelegate?

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = Colors.clear
    }

    required init(coder: NSCoder) {
        super.init(coder: coder)
    }
    // A bunch of class methods
}

这是我的“翻译”的Objective-C .h / .m文件：

HolderView.h：

#import <UIKit/UIKit.h>

@protocol HolderViewDelegate <NSObject>
// delegate methods
@ end

@interface HolderView : UIView

@property (nonatomic, weak) id <HolderViewDelegate> delegate;

@property (nonatomic) CGRect frame;
@property (nonatomic) CGRect parentFrame;

HolderView.m：

- (instancetype)initWithFrame:(CGRect)frame
{
    self.parentFrame = CGRectZero;
    self = [super initWithFrame:frame];
    if (self) {
        [super setFrame:self.parentFrame];
        self.backgroundColor = [UIColor orangeColor]; // Added to see if it's working
        NSLog(@"anyone home?");
    }
    return self;
}

这是Swift和Objective-CUIViewControllers添加以下代码的代码UIView：

ViewController.swift

  func addHolderView() {
    let boxSize: CGFloat = 75.0
    holderView.frame = CGRect(x: view.bounds.width / 2 - boxSize / 2,
                              y: view.bounds.height / 2 - boxSize / 2,
                              width: boxSize,
                              height: boxSize)
    holderView.parentFrame = view.frame
    holderView.delegate = self
    view.addSubview(holderView)
    holderView.addOval()
  }

这是我的“翻译后的” Objective-C视图控制器：

- (void)addHolderView {
    self.boxSize = 75.0; // I added as a global variable, as local returned NULL when I tried locally
    self.holderView.frame = CGRectMake(self.view.bounds.size.height / 2 - self.boxSize / 2,
                                       self.view.bounds.size.width / 2 - self.boxSize / 2,
                                       self.boxSize,
                                       self.boxSize);

    self.holderView.parentFrame = self.view.frame;
    self.holderView = [self.holderView initWithFrame:self.holderView.frame];    

    self.holderView.delegate = self;

    NSLog(@"addHolderView called");
    [self.view addSubview:self.holderView];
}

感谢您的阅读。