有一篇很棒的文章可以更深入地学习它:
https://www.objc.io/issues/3-views/advanced-auto-layout-toolbox/
总之有一套自动布局工具可以让它日复一日的轻松使用:
砌体 (https://github.com/SnapKit/Masonry)
//these two constraints are exactly the same
make.left.greaterThanOrEqualTo(label);
make.left.greaterThanOrEqualTo(label.mas_left);
//creates view.left = view.superview.left + 10
make.left.lessThanOrEqualTo(@10)
EasyPeasy (https://github.com/nakiostudio/EasyPeasy)
// Apply width = 0 and height = 0 constraints
view <- Size()
// Apply width = referenceView.width and height = referenceView.height constraints
view <- Size().like(referenceView)
// Apply width = 100 and height = 100 constraints
view <- Size(100)
// Apply width = 200 and height = 100 constraints
view <- Size(CGSize(width: 200, height: 100)
// Apply left = 0, right = 0, top = 0 and bottom = 0 constraints to its superview
view <- Edges()
// Apply left = 10, right = 10, top = 10 and bottom = 10 constraints to its superview
view <- Edges(10)
// Apply left = 10, right = 10, top = 5 and bottom = 5 constraints to its superview
view <- Edges(UIEdgeInsets(top: 5, left: 10, bottom: 5, right: 10))
PureLayout (https://github.com/PureLayout/PureLayout)
//returns the constraints it creates so you have full control:
let constraint = skinnyView.autoMatchDimension(.Height, toDimension: .Width, ofView: tallView)
// 2 constraints created & activated in one line!
logoImageView.autoCenterInSuperview()
// 4 constraints created & activated in one line!
textContentView.autoPinEdgesToSuperviewEdgesWithInsets(UIEdgeInsets(top: 20.0, left: 5.0, bottom: 10.0, right: 5.0))