IOS autoresizing AutoLayout Size Classes

Autoresizing: As early as possible, only constraints on the parent control (note: To turn off autolayout&size classes to see autoresizing)

Code corresponds to:

The Autoresizingmask property in UIView.h

@property (nonatomic) uiviewautoresizing autoresizingmask; Simple resize. Default is Uiviewautoresizingnone

typedef ns_options (Nsuinteger, uiviewautoresizing) {

Uiviewautoresizingnone = 0,

Uiviewautoresizingflexibleleftmargin = 1 << 0,

Uiviewautoresizingflexiblewidth = 1 << 1,

Uiviewautoresizingflexiblerightmargin = 1 << 2,

Uiviewautoresizingflexibletopmargin = 1 << 3,

Uiviewautoresizingflexibleheight = 1 << 4,

Uiviewautoresizingflexiblebottommargin = 1 << 5

};

AutoLayout: Not only is it possible to constrain the parent control, but it can also be constrained for peers, but it depends on the screen of different devices

Size classes: Divides all dimensions into regular (standard) compact (compact) any (arbitrary) three case combinations, no longer dependent on the dead size, which effectively solves the disadvantage of AutoLayout

Size classes:

But we see that the width and height of the graph are all Any , what does any mean? If weight set to Any , height then the Regular interface element in that state will exist in the state as long as it is height Regular present, both in and out weight Regular Compact . This relationship should be called an inheritance relationship, and the specific four interface descriptions and inheritable interfaces are described below:

• W:compact h:compact Inheritance (w:any h:compact , w:compact h:any , w:any h:any)
• W:regular h:compact Inheritance (w:any h:compact , w:regular h:any , w:any h:any)
• W:compact h:regular Inheritance (w:any h:regular , w:compact h:any , w:any h:any)
• W:regular h:regular Inheritance (w:any h:regular , w:regular h:any , w:any h:any)

We know that iOS 8 the device interface below can be described as 4, but what exactly is the description of so many devices (Iphone4s,iphone5/5s,iphone6,iphone6 plus,ipad,apple Watch)? After reviewing official documentation and specific practices, the specific correspondence is as follows:

• Iphone4s,iphone5/5s,iphone6
  • Vertical screen: (w:compact h:regular)
  • Horizontal screen: (w:compact h:compact)
• IPhone6 Plus
  • Vertical screen: (w:compact h:regular)
  • Horizontal screen: (w:regular h:compact)
• Ipad
  • Vertical screen: (w:regular h:regular)
  • Horizontal screen: (w:regular h:regular)
• Apple Watch (guess)
  • Vertical screen: (w:compact h:compact)
  • Horizontal screen: (w:compact h:compact)

Code Correspondence: Uitraitcollection

UIViewController.h

-(void) Willtransitiontotraitcollection: (uitraitcollection *) newcollection withtransitioncoordinator: (ID < uiviewcontrollertransitioncoordinator>) Coordinator Ns_available_ios (8_0);

UITraitCollection.h (normal view)

/*! Trait environments expose a Trait collection that describes their environment. */

@protocol uitraitenvironment <NSObject>

@property (nonatomic, readonly) uitraitcollection *traitcollection;

/*! To being overridden as needed to provide custom behavior when the environment's traits change. */

-(void) Traitcollectiondidchange: (uitraitcollection *) previoustraitcollection;

@end

AutoLayout:

Code corresponds to:

Nslayoutconstraint

Note: Hand code auto layout turns off the following properties of UIView first

1.-(BOOL) translatesautoresizingmaskintoconstraints Ns_available_ios (6_0); Default YES

2.1VFL language

+ (Nsarray *) Constraintswithvisualformat: (NSString *) format options: (nslayoutformatoptions) OPTs metrics: ( Nsdictionary *) Metrics Views: (Nsdictionary *) views;

2.2 Pure Code

+ (Instancetype) Constraintwithitem: (id) view1 attribute: (nslayoutattribute) attr1 Relatedby: (nslayoutrelation) Relation Toitem: (id) view2 attribute: (nslayoutattribute) attr2 multiplier: (cgfloat) Multiplier constant: (cgfloat) C;

Details: http://www.cnblogs.com/zhw511006/p/3998534.html

IOS autoresizing AutoLayout Size Classes