一、代码演示

1、设置第一个label

2、设置第二个label

3、设置第三个label

4、运行后的效果

例子2:

二、属性

/// 左侧

@property (nonatomic, strong, readonly) MASConstraint *left;

/// 上侧

@property (nonatomic, strong, readonly) MASConstraint *top;

/// 右侧

@property (nonatomic, strong, readonly) MASConstraint *right;

/// 下侧

@property (nonatomic, strong, readonly) MASConstraint *bottom;

/// 首部

@property (nonatomic, strong, readonly) MASConstraint *leading;

/// 底部

@property (nonatomic, strong, readonly) MASConstraint *trailing;

/// 宽

@property (nonatomic, strong, readonly) MASConstraint *width;

/// 高

@property (nonatomic, strong, readonly) MASConstraint *height;

/// 横向中点

@property (nonatomic, strong, readonly) MASConstraint *centerX;

/// 纵向中点

@property (nonatomic, strong, readonly) MASConstraint *centerY;

/// 文本基线

@property (nonatomic, strong, readonly) MASConstraint *baseline;

// 在Masonry的源码中我们可以看到他们对应的NSLayoutAttribute的属性对应如下

1、- (MASConstraint *)left {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeLeft];

}

2、- (MASConstraint *)top {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeTop];

}

3、- (MASConstraint *)right {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeRight];

}

4、- (MASConstraint *)bottom {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeBottom];

}

5、- (MASConstraint *)leading {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeLeading];

}

6、- (MASConstraint *)trailing {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeTrailing];

}

7、- (MASConstraint *)width {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeWidth];

}

8、- (MASConstraint *)height {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeHeight];

}

9、- (MASConstraint *)centerX {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeCenterX];

}

10、- (MASConstraint *)centerY {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeCenterY];

}

11、- (MASConstraint *)baseline {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeBaseline];

}

三、iOS8之后Masonry新出了几个属性：

/// 距离边框的距离，等同于选中Storyboard的Constrain to margins后加约束

@property (nonatomic, strong, readonly) MASConstraint *leftMargin;

@property (nonatomic, strong, readonly) MASConstraint *rightMargin;

@property (nonatomic, strong, readonly) MASConstraint *topMargin;

@property (nonatomic, strong, readonly) MASConstraint *bottomMargin;

@property (nonatomic, strong, readonly) MASConstraint *leadingMargin;

@property (nonatomic, strong, readonly) MASConstraint *trailingMargin;

@property (nonatomic, strong, readonly) MASConstraint *centerXWithinMargins;

@property (nonatomic, strong, readonly) MASConstraint *centerYWithinMargins;

- (MASConstraint *)leftMargin {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeLeftMargin];

}

- (MASConstraint *)rightMargin {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeRightMargin];

}

- (MASConstraint *)topMargin {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeTopMargin];

}

- (MASConstraint *)bottomMargin {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeBottomMargin];

}

- (MASConstraint *)leadingMargin {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeLeadingMargin];

}

- (MASConstraint *)trailingMargin {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeTrailingMargin];

}

- (MASConstraint *)centerXWithinMargins {

return [self addConstraintWithLayoutAttribute:NSLayoutAttributeCenterXWithinMargins];

}