NSWindow 是 NSResponder 的子类,您不应该在其中绘图。
解决方案:
您应该覆盖“contentView”变量(自定义窗口子类)并将其图层设置为您在“contentView”的 set 方法中创建的 CAGradientLayer
创建 NSView 的自定义子类并将其设置为 Storyboard/XIB 中自定义窗口的视图。在视图中,您可以覆盖 drawInRect 或使用图层方法。
另外看这里How to draw custom NSWindow
快速脏代码如下
import Cocoa
class CustomWindow : NSWindow {
override init(contentRect: NSRect, styleMask aStyle: Int, backing bufferingType: NSBackingStoreType, defer flag: Bool) {
super.init(contentRect: contentRect, styleMask: aStyle, backing: bufferingType, defer: flag)
}
override var contentView: AnyObject {
set {
var view = newValue as! NSView
view.wantsLayer = true
let colorTop = NSColor(red: 48 / 255, green: 35 / 255, blue: 174 / 255, alpha: 1).CGColor
let colorBottom = NSColor(red: 200 / 255, green: 109 / 255, blue: 215 / 255, alpha: 1).CGColor
let gradient = CAGradientLayer()
gradient.colors = [ colorTop, colorBottom]
gradient.locations = [ 0.0, 1.0]
view.layer = gradient
super.contentView = view
}
get {
return super.contentView
}
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
解决方案2:
import Cocoa
class CustomView : NSView {
override func drawRect(dirtyRect: NSRect) {
let colorTop = NSColor(red: 48 / 255, green: 35 / 255, blue: 174 / 255, alpha: 1)
let colorBottom = NSColor(red: 200 / 255, green: 109 / 255, blue: 215 / 255, alpha: 1)
let gradient = NSGradient(colors: [colorTop, colorBottom])
gradient.drawInRect(dirtyRect, angle: 45)
}
}
如果您需要自定义标题栏,请查看此处。这是很多工作。
PS:请记住,实际绘图是在 NSView 中完成的