VFL Syntax-Basics

1 #import "ViewController.h"2 3 @interfaceViewcontroller ()4 {5UIView *_redview;6UIView *_blueview;7UIView *_cyanview;8 }9 @endTen  One @implementationViewcontroller A  -- (void) Viewdidload { - [Super Viewdidload]; the     //1. No longer need to set frame coordinates -_redview =[[UIView alloc] init]; -_redview.backgroundcolor =[Uicolor Redcolor]; -     //2. May conflict with Autoresizingmask +_redview.translatesautoresizingmaskintoconstraints =NO; - [Self.view Addsubview:_redview]; +      A_blueview =[[UIView alloc] init]; at_blueview.backgroundcolor =[Uicolor Bluecolor]; -_blueview.translatesautoresizingmaskintoconstraints =NO; - [Self.view Addsubview:_blueview]; -      -_cyanview =[[UIView alloc] init]; -_cyanview.backgroundcolor =[Uicolor Cyancolor]; in_cyanview.translatesautoresizingmaskintoconstraints =NO; - [Self.view Addsubview:_cyanview]; to      +     //Constraints -  the     /* * 1.view1: Set Constraints on Objects View1 this object $ 2.attribute: Refers to View1.attribute set what kind of constraintPanax Notoginseng 3.relatedBy: Relationship equals - 4.view2: Referential the 5.attribute:view2.attribute + 6.multiplier: Multiplier factor A 7.constant: Deviation value the       + 8. Calculation: VIEW1.ATTR1 = View2.attr3*multiplier + constant -     */ $      $     //Create a left spacing constraint from a parent view -Nslayoutconstraint *conleft = [Nslayoutconstraint constraintwithitem:_redview attribute:nslayoutattributeleft Relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeleft Multiplier:1.0constant -]; -     //Create a right spacing constraint theNslayoutconstraint *conright = [Nslayoutconstraint constraintwithitem:_redview attribute:nslayoutattributeright Relatedby:nslayoutrelationequal ToItem:self.view attribute:nslayoutattributeright Multiplier:1.0constant:- -]; -     //Create top spacingWuyiNslayoutconstraint *contop = [Nslayoutconstraint constraintwithitem:_redview attribute:nslayoutattributetop Relatedby:nslayoutrelationequal ToItem:self.view attribute:nslayoutattributetop Multiplier:1.0constant -]; the     //Create a height constraint -Nslayoutconstraint *conheight = [Nslayoutconstraint constraintwithitem:_redview attribute:nslayoutattributeheight Relatedby:nslayoutrelationequal ToItem:self.view attribute:nslayoutattributeheight Multiplier:0.2constant0]; Wu      -     //Create bottom Spacing About     //nslayoutconstraint *conbottom = [Nslayoutconstraint constraintwithitem:_redview attribute: Nslayoutattributebottom relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributebottom multiplier:1.0 constant:-20]; $      - [Self.view Addconstraints:@[conleft,conright,contop,conheight]]; -      -      A      +      the     //NSLog (@ "%@", Nsstringfromcgrect (_redview.frame)); -      $     //Create a left spacing constraint from a parent view theNslayoutconstraint *blueleft = [Nslayoutconstraint constraintwithitem:_blueview attribute:nslayoutattributeleft Relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeleft Multiplier:1.0constant -]; the     //Create a right spacing constraint theNslayoutconstraint *blueright = [Nslayoutconstraint constraintwithitem:_blueview attribute:nslayoutattributeright Relatedby:nslayoutrelationequal ToItem:self.view attribute:nslayoutattributeright Multiplier:0.5constant:-Ten]; the     //Create top spacing -Nslayoutconstraint *bluetop = [Nslayoutconstraint constraintwithitem:_blueview attribute:nslayoutattributetop Relatedby:nslayoutrelationequal Toitem:_redview Attribute:nslayoutattributebottom Multiplier:1.0constant -]; in     //Create a height constraint the     //nslayoutconstraint *blueheight = [Nslayoutconstraint constraintwithitem:_redview attribute: Nslayoutattributeheight relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeheight multiplier:0.2 constant:0]; the      About     //Create bottom Spacing theNslayoutconstraint *bluebottom = [Nslayoutconstraint constraintwithitem:_blueview attribute:NSLayoutAttributeBottom Relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributebottom Multiplier:1.0constant:- -]; the      the [Self.view Addconstraints:@[blueleft,blueright,bluetop,bluebottom]]; +      -      the     Bayi      the      the     //Create a left spacing constraint from a parent view -     //nslayoutconstraint *cyanleft = [Nslayoutconstraint constraintwithitem:_cyanview attribute:nslayoutattributeleft Relatedby:nslayoutrelationequal Toitem:_blueview attribute:nslayoutattributeright multiplier:1.0 constant:20]; -Nslayoutconstraint *cyanleft = [Nslayoutconstraint constraintwithitem:_cyanview attribute: Nslayoutattributeleftmargin relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeright Multiplier0.5constantTen]; the     //Create a right spacing constraint theNslayoutconstraint *cyanright = [Nslayoutconstraint constraintwithitem:_cyanview attribute:nslayoutattributeright Relatedby:nslayoutrelationequal ToItem:self.view attribute:nslayoutattributeright Multiplier:1.0constant:- -]; the     //Create top spacing theNslayoutconstraint *cyantop = [Nslayoutconstraint constraintwithitem:_cyanview attribute:nslayoutattributetop Relatedby:nslayoutrelationequal Toitem:_redview Attribute:nslayoutattributebottom Multiplier:1.0constant -]; -     //Create a height constraint the     //nslayoutconstraint *blueheight = [Nslayoutconstraint constraintwithitem:_redview attribute: Nslayoutattributeheight relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeheight multiplier:0.2 constant:0]; the      the     //Create bottom Spacing94Nslayoutconstraint *cyanbottom = [Nslayoutconstraint constraintwithitem:_cyanview attribute:NSLayoutAttributeBottom Relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributebottom Multiplier:1.0constant:- -]; the      the [Self.view Addconstraints:@[cyanleft,cyanright,cyantop,cyanbottom]]; the 98 } About  --(void) Touchesbegan: (Nsset *) touches withevent: (Uievent *)Event101 {102NSLog (@"%@", Nsstringfromcgrect (_redview.frame));103 }104  the- (void) didreceivememorywarning {106 [Super didreceivememorywarning];107     108 }109  the @end

VFL Syntax-Basics