使用xibs嵌套@IBDesignable？

Question

我试图在iOS上创建一个基于组件的系统，我想做以下工作：

1. 创建一个"PaddedView“组件，它在任何添加的子组件周围都有8px的空间，比如容器类型组件。
2. 将另一个IBDesignable视图添加到故事板上的PaddedView中，并查看两个呈现。

这个是可能的吗？

现在，对于所有IBDesignable组件，我使用以下超类从xibs加载它们的视图：

import Foundation
import UIKit

@IBDesignable
class SKDesignableView: UIView {
    var view: UIView?

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

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.loadXib()
    }

    func loadXib() {
        self.view = self.viewFromXib()
        self.view!.frame = self.bounds
        self.view!.autoresizingMask = [UIViewAutoresizing.flexibleWidth, UIViewAutoresizing.flexibleHeight]
        self.addSubview(self.view!)
    }

    func viewFromXib() -> UIView {
        let bundle = UINib(nibName: String(describing: self.getType()), bundle: Bundle(for: self.getType()))
        let views = bundle.instantiate(withOwner: self, options: nil)
        return views.first as! UIView
    }

    func getType() -> AnyClass {
        fatalError()
    }
}

如何为其他IBDesignables创建占位符？

Answer 1

视图最初包含子视图，因此将容器视图作为子视图添加到任何需要子组件的组件中。

func loadXib() {
        var subview: UIView? = nil
        if self.subviews.count > 0 {
            subview = self.subviews[0]
        }
        subview?.removeFromSuperview()

        self.view = self.viewFromXib()
        self.view!.frame = self.bounds
        self.view!.autoresizingMask = [UIViewAutoresizing.flexibleWidth, UIViewAutoresizing.flexibleHeight]

        if let subview = subview {
            let lConstraint = NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.leading, relatedBy: NSLayoutRelation.equal,
                    toItem: self.view!, attribute: NSLayoutAttribute.leading, multiplier: 1, constant: 8)
            let rConstraint = NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.trailing, relatedBy: NSLayoutRelation.equal,
                    toItem: self.view!, attribute: NSLayoutAttribute.trailing, multiplier: 1, constant: -8)
            let tConstraint = NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal,
                    toItem: self.view!, attribute: NSLayoutAttribute.top, multiplier: 1, constant: 8)
            let bConstraint = NSLayoutConstraint(item: subview, attribute: NSLayoutAttribute.bottom, relatedBy: NSLayoutRelation.equal,
                    toItem: self.view!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: -8)
            self.view!.addSubview(subview)
            self.view!.addConstraints([lConstraint, rConstraint, tConstraint, bConstraint])
        }
        self.addSubview(self.view!)
    }

这种方法可以推广到标签等，以添加多个子视图。