我对SWIFT和Mac开发非常陌生。现在我正在尝试使用NSLayoutContraint。
var boardView:NSView = NSView()
boardView.wantsLayer = true
boardView.layer!.backgroundColor = NSColor.redColor().CGColor
//boardView.setFrameSize(NSSize(width: 200, height: 200))
//boardView.setFrameOrigin(NSPoint(x: 50, y: 50))
self.view.addSubview(boardView)
self.view.addConstraint(NSLayoutConstraint(item: boardView, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: .Width, multiplier: 0.8, constant: 0))
self.view.addConstraint(NSLayoutConstraint(item: boardView, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: .Height, multiplier: 0.8, constant: 0))
println(self.view.frame)
println(boardView.frame)
这些代码保留在ViewController.viewDidLoad（）中，但在运行代码后无法显示该窗口。控制台输出是：
(0.0, 0.0, 800.0, 600.0)
(0.0, 0.0, 0.0, 0.0)
然后我设置boardView的宽度和高度（取消注释第5,6行）。视图现在可以显示，但窗口大小是boardView的约束，而不是适合外窗的boardView。
现在我对此非常困惑。非常感谢您的帮助！
我将println复制到viewDidLayout（），输出如下：
(0.0, 0.0, 800.0, 600.0)
(0.0, 0.0, 0.0, 0.0)
(0.0, 0.0, 0.0, 0.0)
(0.0, 0.0, 0.0, 0.0)
发生了一些错误/警告。
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: conn 0x4fc23 token 0x11ffffffffff2ad
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: Backtrace (at 790422):
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 0 CoreGraphics 0x00007fff90873501 CGSBacktraceCreate + 59
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 1 CoreGraphics 0x00007fff908c8244 _ZN16CGSUpdateManager14disable_updateEv + 84
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 2 AppKit 0x00007fff97dcdd15 -[NSWindow disableScreenUpdatesUntilFlush] + 127
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 3 AppKit 0x00007fff97dcc95a -[NSView(NSInternal) geometryInWindowDidChange] + 185
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 4 AppKit 0x00007fff97dcc581 -[NSView _invalidateFocus] + 437
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 5 AppKit 0x00007fff97de9e67 -[NSView setFrameSize:] + 1735
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 6 AppKit 0x00007fff97e5f87e -[NSThemeFrame setFrameSize:] + 473
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 7 AppKit 0x00007fff97de8f83 -[NSView setFrame:] + 464
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 8 AppKit 0x00007fff97e5537f -[NSView resizeWithOldSuperviewSize:] + 1206
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 9 AppKit 0x00007fff97f5bd15 -[NSView layoutSubtreeIfNeeded] + 810
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 10 AppKit 0x00007fff97f5b8ba _NSViewLayoutSubtreesThatUseAutolayoutIfNeeded + 71
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 11 AppKit 0x00007fff97f5b841 -[NSWindow(NSConstraintBasedLayout) _layoutViewTree] + 84
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 12 AppKit 0x00007fff97f7ad3d -[NSWindow(NSConstraintBasedLayout) layoutIfNeeded] + 246
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 13 AppKit 0x00007fff97e1f52e _handleWindowNeedsDisplayOrLayoutOrUpdateConstraints + 612
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 14 AppKit 0x00007fff98555171 __83-[NSWindow _postWindowNeedsDisplayOrLayoutOrUpdateConstraintsUnlessPostingDisabled]_block_invoke1540 + 46
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 15 CoreFoundation 0x00007fff9295d127 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 16 CoreFoundation 0x00007fff9295d080 __CFRunLoopDoObservers + 368
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 17 CoreFoundation 0x00007fff9294f188 __CFRunLoopRun + 872
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 18 CoreFoundation 0x00007fff9294ebd8 CFRunLoopRunSpecific + 296
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 19 HIToolbox 0x00007fff9900456f RunCurrentEventLoopInMode + 235
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 20 HIToolbox 0x00007fff990041ee ReceiveNextEventCommon + 179
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 21 HIToolbox 0x00007fff9900412b _BlockUntilNextEventMatchingListInModeWithFilter + 71
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 22 AppKit 0x00007fff97e1c8ab _DPSNextEvent + 978
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 23 AppKit 0x00007fff97e1be58 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 346
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 24 AppKit 0x00007fff97e11af3 -[NSApplication run] + 594
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 25 AppKit 0x00007fff97d8e244 NSApplicationMain + 1832
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 26 GameBegin_Mac 0x000000010000df0d main + 109
Aug 31 19:14:33 Hans-Bogenmacher.local GameBegin_Mac[28780] <Warning>: void CGSUpdateManager::log() const: 27 libdyld.dylib 0x00007fff967715c9 start + 1
我将约束更改为：
self.view.addConstraint(NSLayoutConstraint(item: boardView!, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: .CenterX, multiplier: 1, constant: 0))
self.view.addConstraint(NSLayoutConstraint(item: boardView!, attribute: NSLayoutAttribute.CenterY, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: .CenterY, multiplier: 1, constant: 0))
self.view.addConstraint(NSLayoutConstraint(item: boardView!, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: .Width, multiplier: 0.8, constant: 0))
self.view.addConstraint(NSLayoutConstraint(item: boardView!, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: .Height, multiplier: 0.8, constant: 0))
但它没用，控制台输出是：
(0.0, 0.0, 800.0, 480.0)
(0.0, 0.0, 0.0, 0.0)
(0.0, 0.0, 0.0, 0.0)
(0.0, 0.0, 0.0, 0.0)
只需调用boardView.translatesAutoresizingMaskIntoConstraints = false就行了！谢谢！
但现在我无法完成要求：
boardView.frame.width = self.view.frame.width * 0.8
boardView.frame.centerX = self.view.frame.centerX
boardView.frame.height = self.view.frame.height * 0.1
boardView.frame.top = self.view.frame.height * 0.2
现在我知道如何做第1,2,3行，但是我不能将Top到高度绑定，如何进行第4行？谢谢！