如何保持窗口始终在顶部与Swift？

Question

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• Xcode版本7.3 (7D175)
• Swift 2.2版
• Mac版OS X El Capitan 10.11.4

我想为Mac制作一个桌面应用程序，我已经设置了窗口级别，但它不工作。

Answer 1

您需要检查窗口!=在任何自定义代码之前为零

class ViewController: NSViewController {
    var addedObserver = false

    override func viewDidLoad() {
        super.viewDidLoad()

        if let window = self.view.window {
            // custom window here
            window.level = Int(CGWindowLevelForKey(.FloatingWindowLevelKey))
        } else {
            addedObserver = true
            self.addObserver(self, forKeyPath: "view.window", options: [.New, .Initial], context: nil)
        }
    }

    override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
        if let window = self.view.window {
            // custom window here
            window.level = Int(CGWindowLevelForKey(.FloatingWindowLevelKey))
        }
    }

    deinit {
        if addedObserver {
            self.removeObserver(self, forKeyPath: "view.window")
        }
    }
}

Answer 2

让你的应用程序总是在Swift 5的其他应用程序之上是如此简单。

override func viewDidAppear() {
    view.window?.level = .floating
}

Answer 3

还在测试中，但这是在Swift 4中的幼虫的答案，它似乎是有效的。

var observingFloat = false

 override func viewDidLoad() {
        super.viewDidLoad()
        self.view.wantsLayer = true

        if self.view.window != nil {
            NSApplication.shared.windows.first?.level = NSWindow.Level(rawValue: 1)
        } else {
            observingFloat = true
            self.addObserver(self, forKeyPath: "view.window", options: [.new, .initial], context: nil)
        }
    }

    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        if self.view.window != nil {
            NSApplication.shared.windows.first?.level = NSWindow.Level(rawValue: 1)
        }
    }