iOS Development AutoLayout Code implementation AutoLayout Use summary

1. Theoretical part

Demo Example 1:

UIView *blueview = [[UIView alloc] init];    Blueview.backgroundcolor = [Uicolor Bluecolor];    Do not convert Autoresizingmask to AutoLayout constraint blueview.translatesautoresizingmaskintoconstraints = NO;        [Self.view Addsubview:blueview]; Add width constraint: nslayoutconstraint *widthconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributewidth relatedby:nslayoutrelationequal Toitem:nil Attribute:nslayoutattributenotanattribute    multiplier:0.0 constant:100];        [Blueview Addconstraint:widthconstraint]; Add height constraint: nslayoutconstraint *heightconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributeheight relatedby:nslayoutrelationequal Toitem:nil Attribute:nslayoutattributenotanattribute    multiplier:0.0 constant:100];        [Blueview Addconstraint:heightconstraint]; Add right constraint: Blueview to the right of the parent control has a spacing of 10 nslayoutconstraint *rightconstraint = [Nslayoutconstraint constraintwithitem: Blueview Attribute:nslayoutattributerigHT relatedby:nslayoutrelationequal ToItem:self.view attribute:nslayoutattributeright multiplier:1.0 constant:-10];        [Self.view Addconstraint:rightconstraint]; Add top constraint: The top of Blueview is 10 of the distance from the top of the parent control nslayoutconstraint *topconstraint = [Nslayoutconstraint constraintwithitem: Blueview attribute:nslayoutattributetop relatedby:nslayoutrelationequal toItem:self.view attribute:    Nslayoutattributetop multiplier:1.0 Constant:10]; [Self.view Addconstraint:topconstraint];

Effect:

Demo Example 2:

/** * Width height is 100, vertically horizontally centered in the parent control */-(void) test2{UIView *blueview = [[UIView alloc] init];    Blueview.backgroundcolor = [Uicolor Bluecolor];    Do not convert Autoresizingmask to AutoLayout constraint blueview.translatesautoresizingmaskintoconstraints = NO;        [Self.view Addsubview:blueview]; Add width constraint: Half of the parent control nslayoutconstraint *widthconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributewidth relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributewidth    multiplier:0.5 constant:0];        [Self.view Addconstraint:widthconstraint]; Add height constraint: Half of the parent control nslayoutconstraint *heightconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributeheight relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeheight    multiplier:0.5 constant:0];        [Self.view Addconstraint:heightconstraint]; Horizontal center Nslayoutconstraint *centerxconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributecenterx relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributecenterx    multiplier:1.0 constant:0];        [Self.view Addconstraint:centerxconstraint]; Center vertically Nslayoutconstraint *centeryconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributecentery relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributecentery    multiplier:1.0 constant:0]; [Self.view addconstraint:centeryconstraint];}

Effect:

Demo Example 3:

-(void) test3{UIView *blueview = [[UIView alloc] init];    Blueview.backgroundcolor = [Uicolor Bluecolor];    Do not convert Autoresizingmask to AutoLayout constraint blueview.translatesautoresizingmaskintoconstraints = NO;        [Self.view Addsubview:blueview];    UIView *redview = [[UIView alloc] init];    Redview.backgroundcolor = [Uicolor Redcolor];    Do not convert Autoresizingmask to AutoLayout constraint redview.translatesautoresizingmaskintoconstraints = NO; [Self.view addsubview:redview];//Add width constraint: 100/************************** Blue **************************///Add height approx. Bundle: Nslayoutconstraint *heightconstraint = [Nslayoutconstraint constraintwithitem:blueview attribute: Nslayoutattributeheight relatedby:nslayoutrelationequal Toitem:nil Attribute:nslayoutattributenotanattribute    multiplier:0.0 constant:40];        [Blueview Addconstraint:heightconstraint]; Add left constraint: Blueview the left side of the parent control has a distance of 20 nslayoutconstraint *leftconstraint = [Nslayoutconstraint constraintwithitem: Blueview AttribuTe:nslayoutattributeleft relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributeleft    multiplier:1.0 CONSTANT:20];        [Self.view Addconstraint:leftconstraint]; Add right constraint: Blueview to the right of the parent control has a spacing of 20 nslayoutconstraint *rightconstraint = [Nslayoutconstraint constraintwithitem: Blueview attribute:nslayoutattributeright relatedby:nslayoutrelationequal toItem:self.view attribute:    Nslayoutattributeright multiplier:1.0 constant:-20];        [Self.view Addconstraint:rightconstraint]; Add top constraint: The top of Blueview is 20 of the distance from the top of the parent control nslayoutconstraint *topconstraint = [Nslayoutconstraint constraintwithitem: Blueview attribute:nslayoutattributetop relatedby:nslayoutrelationequal toItem:self.view attribute:    Nslayoutattributetop multiplier:1.0 constant:20];        [Self.view Addconstraint:topconstraint]; /************************** Red **************************///Add height constraint: Blue equal height nslayoutconstraint *heightconstraint2 = [N Slayoutconstraint Constraintwithitem:redview Attribute:nSlayoutattributeheight relatedby:nslayoutrelationequal Toitem:blueview Attribute:nslayoutattributeheight    multiplier:1.0 constant:0];        [Self.view Addconstraint:heightconstraint2]; Add left constraint: redview left = = Parent control's Center x nslayoutconstraint *leftconstraint2 = [Nslayoutconstraint constraintwithitem:redview at Tribute:nslayoutattributeleft relatedby:nslayoutrelationequal ToItem:self.view Attribute:nslayoutattributecenterx    multiplier:1.0 constant:0];        [Self.view Addconstraint:leftconstraint2]; Add top constraint: Redview the top of the Blueview has a distance of 20 from the bottom of the nslayoutconstraint *topconstraint2 = [Nslayoutconstraint constraintwithitem: Redview attribute:nslayoutattributetop relatedby:nslayoutrelationequal toitem:blueview attribute:    Nslayoutattributebottom multiplier:1.0 constant:20];        [Self.view Addconstraint:topconstraint2]; Add right constraint: redview right = = Blueview right Nslayoutconstraint *rightconstraint2 = [Nslayoutconstraint Constraintwithitem:redv Iew Attribute:nslayoutattributeright Relatedby:nslayoUtrelationequal Toitem:blueview attribute:nslayoutattributeright multiplier:1.0 constant:0]; [Self.view Addconstraint:rightconstraint2];}

Effect:

iOS Development AutoLayout Code implementation AutoLayout Use summary