这是我的UISegmentedControl代码：
employeeSegmentedControl = UISegmentedControl(items: items)
employeeSegmentedControl.selectedSegmentIndex = 0
employeeSegmentedControl.backgroundColor = UIColor(red: 41/255, green: 128/255, blue: 185/255, alpha: 1.0)
employeeSegmentedControl.tintColor = UIColor.whiteColor()
employeeSegmentedControl.addTarget(self, action: Selector("indexChanged:"), forControlEvents: .ValueChanged)
self.view.addSubview(employeeSegmentedControl)
employeeSegmentedControl.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.addConstraint(NSLayoutConstraint(item: employeeSegmentedControl, attribute: .Width, relatedBy: .Equal, toItem: self.view, attribute: .Width, multiplier: 1.0, constant: 0.0))
self.view.addConstraint(NSLayoutConstraint(item: employeeSegmentedControl, attribute: .Height, relatedBy: .Equal, toItem: self.searchController.searchBar, attribute: .Height, multiplier: 1.0, constant: 0.0))
self.view.addConstraint(NSLayoutConstraint(item: employeeSegmentedControl, attribute: .CenterX, relatedBy: .Equal, toItem: self.view, attribute: .CenterX, multiplier: 1.0, constant: 0.0))
self.view.addConstraint(NSLayoutConstraint(item: employeeSegmentedControl, attribute: .CenterY, relatedBy: .Equal, toItem: self.searchController.searchBar, attribute: .CenterY, multiplier: 1.2, constant: 0.0))
如您所见，我正在为UISegmentedControl添加约束，但我的应用程序崩溃了 . 这是我的错误消息：
2015-09-03 18:50:52.241员工守护者[14424：11105086] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** [NSLayoutConstraint constraintWithItem：attribute：relatedBy：toItem：attribute：multiplier：constant：]：乘数0或零秒项以及位置第一个属性创建一个等于常量的位置的非法约束 . 必须成对指定位置属性'*** First throw call stack：
我究竟做错了什么？
1 回答
我认为这是因为你设置约束时你的
self.searchController.searchBar是零