equalTo  <=======>   NSLayoutRelationEqual   等于

lessThanOrEqualTo   <======>  NSLayoutRelationLessThanOrEqual   小于或等于

greaterThanOrEqualTo <=======>  NSLayoutRelationGreaterThanOrEqual  大于或等于

MASViewAttribute：视图约束属性

make.width.greaterThanOrEqualTo(@200);
make.width.lessThanOrEqualTo(@400)

<2>//creates view.left = view.superview.left + 10

make.left.lessThanOrEqualTo(@10)

代替NSNumber，使用原始的数据或者结构体设置约束数据

make.top.mas_equalTo(42);
make.height.mas_equalTo(20);
make.size.mas_equalTo(CGSizeMake(50, 100));
make.edges.mas_equalTo(UIEdgeInsetsMake(10, 0, 10, 0));
make.left.mas_equalTo(view).mas_offset(UIEdgeInsetsMake(10, 0, 10, 0));

使用数组NSArray设置约束

make.height.equalTo(@[view1.mas_height, view2.mas_height]);
make.height.equalTo(@[view1, view2]);
make.left.equalTo(@[view1, @100, view3.right]);

.priorityHigh <======> UILayoutPriorityDefaultHigh     高优先级

.priorityMedium <========> between high and low        介于高/低之间

.priorityLow <=========> UILayoutPriorityDefaultLow   低优先级

make.left.greaterThanOrEqualTo(label.mas_left).with.priorityLow();
make.top.equalTo(label.mas_top).with.priority(600);

// make top, left, bottom, right equal view2
    make.edges.equalTo(view2);// make top = superview.top + 5, left = superview.left + 10,
// bottom = superview.bottom - 15, right = superview.right - 20
    make.edges.equalTo(superview).insets(UIEdgeInsetsMake(5, 10, 15, 20))

// All edges but the top should equal those of the superview
make.left.right.and.bottom.equalTo(superview);
make.top.equalTo(otherView);

// make width and height greater than or equal to titleLabel
    make.size.greaterThanOrEqualTo(titleLabel)// make width = superview.width + 100, height = superview.height - 50
    make.size.equalTo(superview).sizeOffset(CGSizeMake(100, -50))

// make centerX and centerY = button1make.center.equalTo(button1)// make centerX = superview.centerX - 5, centerY = superview.centerY + 10 make.center.equalTo(superview).centerOffset(CGPointMake(-5, 10))

// in public/private interface
@property (nonatomic, strong) MASConstraint *topConstraint;
...
// when making constraints
[view1 mas_makeConstraints:^(MASConstraintMaker *make) {self.topConstraint = make.top.equalTo(superview.mas_top).with.offset(padding.top);make.left.equalTo(superview.mas_left).with.offset(padding.left);
}];
...
// then later you can call
[self.topConstraint uninstall];

2.更新约束 mas_updateConstraints

- (void)updateConstraints {[self.growingButton mas_updateConstraints:^(MASConstraintMaker *make) {make.center.equalTo(self);make.width.equalTo(@(self.buttonSize.width)).priorityLow();make.height.equalTo(@(self.buttonSize.height)).priorityLow();make.width.lessThanOrEqualTo(self);make.height.lessThanOrEqualTo(self);}]; //according to apple super should be called at end of method
    [super updateConstraints];
}

3.重新设置mas_remakeConstraints

- (void)changeButtonPosition {

    [self.button mas_remakeConstraints:^(MASConstraintMaker *make) {make.size.equalTo(self.buttonSize);if (topLeft) {make.top.and.left.offset(10);} else {make.bottom.and.right.offset(-10);}}];
}

具体的实例如下：设置view1举例父视图的四周距离均为50

/**
方式一：使用NSLayoutConstraint实现手动布局----------------------------设置UIEdgeInsets----------------------------@interface UIView (UIConstraintBasedLayoutInstallingConstraints)- (NSArray *)constraints NS_AVAILABLE_IOS(6_0);- (void)addConstraint:(NSLayoutConstraint *)constraint NS_AVAILABLE_IOS(6_0);- (void)addConstraints:(NSArray *)constraints NS_AVAILABLE_IOS(6_0);- (void)removeConstraint:(NSLayoutConstraint *)constraint- (void)removeConstraints:(NSArray *)constraints NS_AVAILABLE_IOS(6_0);
*/
-(void)LayoutConstraint
{UIView *superView = self.view;UIView *view1 = [[UIView alloc]init];view1 .translatesAutoresizingMaskIntoConstraints = NO;view1.backgroundColor = [UIColor redColor];[superView addSubview:view1];//设置距离父视图边界距离UIEdgeInsets pading = UIEdgeInsetsMake(50, 50, 50, 50);//添加给view1约束
    [superView addConstraints:@[[NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:superView attribute:NSLayoutAttributeTop multiplier:1.0 constant:pading.top],[NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:superView attribute:NSLayoutAttributeLeft multiplier:1.0 constant:pading.left],[NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:superView attribute:NSLayoutAttributeBottom multiplier:1.0 constant:-pading.bottom],[NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:superView attribute:NSLayoutAttributeRight multiplier:1.0 constant:-pading.right],]];
}

/**
方法二：使用block  @implementation MAS_VIEW (MASAdditions)----------------------------设置offset偏移 或者 边缘edges
----------------------------- (NSArray *)mas_makeConstraints:(void(^)(MASConstraintMaker *))block
- (NSArray *)mas_updateConstraints:(void(^)(MASConstraintMaker *))block
- (NSArray *)mas_remakeConstraints:(void(^)(MASConstraintMaker *make))block
*/
-(void)LayoutForMASConstraintMaker
{UIView *superView = self.view;UIView *view1 = [[UIView alloc]init];view1.backgroundColor = [UIColor redColor];[superView addSubview:view1];//设置距离父视图边界距离UIEdgeInsets pading = UIEdgeInsetsMake(50, 50, 50, 50);//添加给view1约束[view1 mas_makeConstraints:^(MASConstraintMaker *make) {make.top.equalTo(superView.mas_top).with.offset(pading.top);make.left.equalTo(superView.mas_left).with.offset(pading.left);make.bottom.equalTo(superView.mas_bottom).with.offset(-pading.bottom);make.right.equalTo(superView.mas_right).with.offset(-pading.right);//设置代码可以更简单（效果与上面的是一样的）//make.edges.equalTo(superView).with.insets(pading);
    }];
}

/**
方式三：使用block  @implementation MAS_VIEW (MASAdditions)----------------------------设置margin距离----------------------------- (NSArray *)mas_makeConstraints:(void(^)(MASConstraintMaker *))block- (NSArray *)mas_updateConstraints:(void(^)(MASConstraintMaker *))block- (NSArray *)mas_remakeConstraints:(void(^)(MASConstraintMaker *make))block
*/
-(void)LayoutForMASConstraintMakerWithMargin
{UIView *superView = self.view;UIView *view1 = [[UIView alloc]init];view1.backgroundColor = [UIColor redColor];[superView addSubview:view1];//添加给view1约束[view1 mas_makeConstraints:^(MASConstraintMaker *make) {make.topMargin.equalTo(superView.mas_top).with.offset(50);make.leftMargin.equalTo(superView.mas_left).with.offset(50);make.bottomMargin.equalTo(superView.mas_bottom).with.offset(-50);make.rightMargin.equalTo(superView.mas_right).with.offset(-50);}];
}

/**方式四：使用block  @implementation MAS_VIEW (MASAdditions)----------------------------设置center和size----------------------------- (NSArray *)mas_makeConstraints:(void(^)(MASConstraintMaker *))block- (NSArray *)mas_updateConstraints:(void(^)(MASConstraintMaker *))block- (NSArray *)mas_remakeConstraints:(void(^)(MASConstraintMaker *make))block*/
-(void)LayoutForMASConstraintMakerWithCenterWidthHeight
{UIView *superView = self.view;UIView *view1 = [[UIView alloc]init];view1.backgroundColor = [UIColor redColor];[superView addSubview:view1];//添加给view1约束[view1 mas_makeConstraints:^(MASConstraintMaker *make) {make.centerX.equalTo(superView);make.centerY.equalTo(superView);make.size.equalTo(superView).sizeOffset(CGSizeMake(-100,-100));}];
}