如何使透明的NSView子类处理鼠标事件？

要使透明的NSView子类处理鼠标事件，您需要遵循以下步骤：

创建一个透明的NSView子类。

class CustomView: NSView {
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        setupView()
    }

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

    private func setupView() {
        wantsLayer = true
        layer?.backgroundColor = NSColor.clear.cgColor
    }
}

重写hitTest(_:)方法。

override func hitTest(_ point: NSPoint) -> NSView? {
    let hitView = super.hitTest(point)
    return hitView == self ? nil : hitView
}

添加鼠标事件监听器。

override func updateTrackingAreas() {
    super.updateTrackingAreas()

    if let trackingArea = trackingArea {
        removeTrackingArea(trackingArea)
    }

    let options: NSTrackingArea.Options = [.mouseEnteredAndExited, .activeInKeyWindow]
    let trackingArea = NSTrackingArea(rect: bounds, options: options, owner: self, userInfo: nil)
    addTrackingArea(trackingArea)
}

override func mouseEntered(with event: NSEvent) {
    Swift.print("Mouse entered")
}

override func mouseExited(with event: NSEvent) {
    Swift.print("Mouse exited")
}

现在，您的透明NSView子类将处理鼠标事件，并在鼠标进入和退出视图时触发mouseEntered和mouseExited方法。