問題與計劃增加的視圖

你好我programmaticaly加入這樣問題與計劃增加的視圖

 let xPos = (self.view.frame.size.width - 200)/2 
     self.headerLabel = UILabel(frame: CGRect(x: xPos, y: 50.0, width: 200.0, height: 100.0)) 
     self.shopButton = UIButton(frame: CGRect(x: xPos, y: 150.0, width: 200.0, height: 40.0)) 
     self.createButton = UIButton(frame: CGRect(x: xPos, y: 230.0, width: 200.0, height: 40.0)) 
     self.orLabel = UILabel(frame: CGRect(x: xPos, y: 200.0, width: 200.0, height: 20.0))

問題的一些看法是，當我旋轉裝置，景觀模式，反之亦然我的看法是一致的左側。我怎樣才能防止它？

來源

2017-02-27 Mighty Codder

你可以找到一些好的文檔/後有：http://stackoverflow.com/questions/27473810/how-to-change-layout-constraints-programmatically-on -display-rotation和https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/AutolayoutPG/WorkingwithConstraintsinInterfaceBuidler.html – Balanced

在視圖中使用NSLayoutConstaint

其超強的看法添加約束例如

let horizontalConstraint = NSLayoutConstraint.init(item: view, attribute: .centerX, relatedBy: .equal, toItem: view.superview, attribute: .centerX, multiplier: 1, constant: 1) 
     horizontalConstraint.isActive = true 

     let verticalConstraint = NSLayoutConstraint.init(item: view, attribute: .centerY, relatedBy: .equal, toItem: view.superview, attribute: .centerY, multiplier: 1, constant: 1) 
     verticalConstraint.isActive = true

來源

2017-02-27 14:39:35