Masonry练习详解

添加约束的方式：

1.通过使用NSLayoutConstraints添加约束到约束数组中,之前必须设置translatesAutoresizingMaskIntoConstraints = NO,即取消自动布局;

2.通过使用MASConstraintMaker在block中添加约束,不需要再设置translatesAutoresizingMaskIntoConstraintst 属性,block内部已经帮助完成;

 

约束的关系：

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

 

 

UIView/NSView

这两个约束完全相同，都是view左边大于等于label的左边位置

make.left.greaterThanOrEqualTo(label）;

make.left.greaterThanOrEqualTo(label.mas_left）;

 

 

NSNumber给约束设置具体的值

<1>//width >= 200 && width <= 400

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]);

 

 

使用优先级设置约束

.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);

 

使用MASCompositeConstraints添加约束

edges：边缘

// 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);

size：大小

// 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))

 

center：中心

// make centerX and centerY = button1
    make.center.equalTo(button1)

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

 

 

有时候，你需要修改现有的约束，以动画或删除/替换约束。在砌体中有几个不同的方法来更新约束。

1.使用设置References

// 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：

/**
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],
    ]];
}

 方式二：

/**
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：

/**
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：

/**
 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));
    }];
}