xcode8 - 带有 Cocoa Touch 框架的 IBInspectable 不起作用？（附代码）

Question

我似乎无法让“titleText”IBInspectable 属性正常工作。我有一个带有 UILabel 的简单框架视图，我创建了一个 IBInspectable 变量“titleText”。我注意到可检查的“层”变量按预期工作，但不是我的自定义“titleText”，它应该使用这个框架更新主视图。

问题是：

1. Interface Builder 不更新titleLabel？（即在设计时）即我期望这应该，就像它适用于“层”项目一样。

2. 在运行时，titleLabel 的值也没有达到我在 IB 中设置的值。请注意，当我运行时，我得到以下输出，即产生此输出的代码发现“self.titleLabel”实际上是 nil？

代码摘要

(a) gcCustomView.xib 快照

(b) gcCustomerView.swift

import UIKit

@IBDesignable 
class gcCustomView: UIView {

    @IBOutlet weak var titleLabel: UILabel!
    @IBInspectable var titleText: String = "Default" {
        didSet {
            if  self.titleLabel != nil {
                self.titleLabel.text = titleText
            } else {
                NSLog("Could not set title text as label.text was nil : was trying to set to \(titleText)")
            }
        }
    }


    @IBInspectable var cornerRadius: CGFloat = 0 {
        didSet {
            layer.cornerRadius = cornerRadius
            layer.masksToBounds = cornerRadius > 0
        }
    }
    @IBInspectable var borderWidth: CGFloat = 0 {
        didSet {
            layer.borderWidth = borderWidth
        }
    }
    @IBInspectable var borderColor: UIColor? {
        didSet {
            layer.borderColor = borderColor?.cgColor
        }
    }


    override init(frame: CGRect) {
        super.init(frame: frame)
        commitInit()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commitInit()
    }

    // Private

    func commitInit() {
        if self.subviews.count == 0 {
            print("Loading Nib")
            //let bundle = Bundle(forClass: self.dynamicType)
            let bundle = Bundle(for: type(of: self))
            let nib = UINib(nibName: "gcCustomView", bundle: bundle)
            let view = nib.instantiate(withOwner: self, options: nil)[0] as! UIView
            view.frame = bounds
            view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
            addSubview(view)
        }
    }

}

(c) Main.storyboard 快照

Answer 1

选择gcCustomView.xib File's Owner将类名更改为gcCustomerView。

右键单击从Label拖动outlet到File Owner

现在如果你右键单击它应该看起来像这样Label

我做了一个演示项目。它工作正常。如果您仍然有问题，请告诉我。我将在 Github 上上传我的演示项目。

Answer 2

如果你想使用xib确保你在文件所有者中设置了你的类名

先做那个

现在添加类名

并添加IBOutlet

请参阅在情节提要中重用 uiview xib

Answer 3

这是内存问题。标签在这里没有内存。因此它返回 0 而不是在自定义类中加载笔尖，您应该在 ViewController 中加载它。将您的 gcCustomView 替换为以下代码。

gcCustomView.swift

import UIKit

@IBDesignable
class gcCustomView: UIView {

    @IBOutlet weak var titleLabel: UILabel!

    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
        if  self.titleLabel != nil {
            self.titleLabel.text = "Default"
        }
        else {
            NSLog("Could not set title text as label.text was nil : was trying to set to default")
        }
    }
    @IBInspectable var cornerRadius: CGFloat = 0 {
        didSet {
            layer.cornerRadius = cornerRadius
            layer.masksToBounds = cornerRadius > 0
        }
    }
    @IBInspectable var borderWidth: CGFloat = 0 {
        didSet {
            layer.borderWidth = borderWidth
        }
    }
    @IBInspectable var borderColor: UIColor? {
        didSet {
            layer.borderColor = borderColor?.cgColor
        }
    }
    override init(frame: CGRect) {
        super.init(frame: frame)
       // commitInit()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
       // commitInit()
    }
}

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.loadNib()

    }
    func loadNib() {
        let obj = Bundle.main.loadNibNamed("gcCustomView", owner: nil, options: nil)?[0] as! gcCustomView
        obj.frame = (self.view.bounds)
        self.view.addSubview(obj)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

然后构建。它会起作用的。

Answer 4

在自定义视图中删除 Keypath 参数并运行。它对我有用。:)