swift - 如何使用 Swift 3 从 Xib 加载 NSView

Question

如何从Xib中正确加载NSView？

我的代码:

var topLevelArray: NSArray? = nil
let outputValue = AutoreleasingUnsafeMutablePointer<NSArray>(&topLevelArray)

if Bundle.main.loadNibNamed("RadioPlayerView", owner: nil, topLevelObjects: outputValue) {
    let views = outputValue.pointee
    return views.firstObject as! RadioPlayerView
}

topLevelArray = nil
return nil

问题是“outputValue”是一个自动释放指针，一旦我从函数返回，程序就会崩溃并显示 ACCESS_BAD_ADDRESS

Answer 1

我做了一个协议(protocol)和扩展来做到这一点:

import Cocoa

protocol NibLoadable {
    static var nibName: String? { get }
    static func createFromNib(in bundle: Bundle) -> Self?
}

extension NibLoadable where Self: NSView {

    static var nibName: String? {
        return String(describing: Self.self)
    }

    static func createFromNib(in bundle: Bundle = Bundle.main) -> Self? {
        guard let nibName = nibName else { return nil }
        var topLevelArray: NSArray? = nil
        bundle.loadNibNamed(NSNib.Name(nibName), owner: self, topLevelObjects: &topLevelArray)
        guard let results = topLevelArray else { return nil }
        let views = Array<Any>(results).filter { $0 is Self }
        return views.last as? Self
    }
}

用法:

final class MyView: NSView, NibLoadable {
    // ...
}

//创建名为 MyView.xib

的 xib

//... 其他地方:

let myView: MyView? = MyView.createFromNib()