https://github.com/SnapKit/Masonry

https://www.cnblogs.com/qitiandasheng/p/5462085.html
/** mansonry加上这两个宏就不需要考虑父控件了*/

define MAS_SHORTHAND

define MAS_SHORTHAND_GLOBALS

http://www.jianshu.com/p/yuCytg
[sv1 mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo(sv).with.insets(UIEdgeInsetsMake(10, 10, 10, 10));

/* 等价于
make.top.equalTo(sv).with.offset(10);
make.left.equalTo(sv).with.offset(10);
make.bottom.equalTo(sv).with.offset(-10);
make.right.equalTo(sv).with.offset(-10);
*/

/* 也等价于
make.top.left.bottom.and.right.equalTo(sv).with.insets(UIEdgeInsetsMake(10, 10, 10, 10));
*/

}];

作者：里脊串
链接：http://www.jianshu.com/p/yuCytg
來源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

1、Masonry有三个最基本的使用方法###

/** 添加约束 */
[view mas_makeConstraints:<#^(MASConstraintMaker *make)block#>]
/** 更新特定的约束 */
[view mas_updateConstraints:<#^(MASConstraintMaker *make)block#>]
/** 重置所有的约束 */
[view mas_remakeConstraints:<#^(MASConstraintMaker *make)block#>]

就拿第一个方法来举例，其余方法皆雷同

[redView mas_makeConstraints:^(MASConstraintMaker *make{
make.top.equalTo(superView.mas_top).with.offset(10);
make.right.equalTo(superView.mas_right).with.offset(-10);
make.size.equalTo(@(100));
    }];

2、 block里面的写法有很多种，属性也有很多种###

一些基础属性:

/**
*下面这些是基本的设置属性
 1.尺寸：width、height、size
 2.边界：left、leading、right、trailing、top、bottom
 3.中心点：center、centerX、centerY
 4.边界：edges
 5.偏移量：offset、insets、sizeOffset、centerOffset
 6.priority()约束优先级（0~1000），multipler乘因数, dividedBy除因数
 */

有三种关系：

1.等于:  .equalTo 
2.小于:  .lessThanOrEqualTo  
3.大于:  .greaterThanOrEqualTo   

注意了，这个后面跟的参数分为以下三类

• MASViewAttribute

MASViewAttribute	NSLayoutAttribute
view.mas_left	NSLayoutAttributeLeft
view.mas_right	NSLayoutAttributeRight
view.mas_top	NSLayoutAttributeTop
view.mas_bottom	NSLayoutAttributeBottom
view.mas_leading	NSLayoutAttributeLeading
view.mas_trailing	NSLayoutAttributeTrailing
view.mas_width	NSLayoutAttributeWidth
view.mas_height	NSLayoutAttributeHeight
view.mas_centerX	NSLayoutAttributeCenterX
view.mas_centerY	NSLayoutAttributeCenterY
view.mas_baseline	NSLayoutAttributeBaseline

• UIView/NSView

make.left.greaterThanOrEqualTo(label);
make.left.greaterThanOrEqualTo(label.mas_left);

• NSNumber/各种结构体 ： @100

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

• NSArray

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

• 还有一个prioritize属性的东西，是用来设置优先级

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

• 还有对于edges、size、center的使用

// 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))

// make width and height greater than or equal to titleLabelmake.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))

3、ios有一个方法是用来更新或者增加约束的时候调用的###

- (void)updateConstraints { 
[self.growingButton mas_updateConstraints:^(MASConstraintMaker *make) {
 //...
 }]; 
//这个父类方法一定要调用，不然会报错
 [super updateConstraints];
}

如果你想要主动的调用这个系统方法

[self.btn setNeedsUpdateConstraints];

告诉系统，需要改变约束
当然如果你需要实现动画，那么就只需在动画里面执行

[self.btn layoutIfNeed];

注意:在动画里面改变约束是没有动画效果的。