自动布局学习整理

//.分别设置各个相对边距（superview为view的父类视图，下同）
make.left.mas_equalTo(superView.mas_left).mas_offset(10);
make.right.mas_equalTo(superView.mas_right).mas_offset(-10);
make.top.mas_equalTo(superView.mas_left).mas_offset(10);
make.bottom.mas_equalTo(superView.mas_bottom).offset(-10);

//直接连接使用left大于等于每个值
make.left.mas_greaterThanOrEqualTo(10);

//设置宽和高
make.width.mas_equalTo(60);
make.height.mas_equalTo(60);

//.设置center和款高比
make.center.mas_equalTo(superView);
make.width.mas_equalTo(superView).multipliedBy(1.00/3);
make.height.mas_equalTo(superView).multipliedBy(0.25);

//.关于约束优先级,此处要注意约束冲突的问题，统一约束优先级大的生效
make.left.mas_equalTo(100);
make.left.mas_equalTo(view.superview.mas_left).offset(10);
make.left.mas_equalTo(20).priority(700);
make.left.mas_equalTo(40).priorityHigh();
make.left.mas_equalTo(60).priorityMedium();
make.left.mas_equalTo(80).priorityLow();

//.如果你想让view的（x坐标）左边大于等于label的左边，以下两个约束的写法效果一样
 make.left.greaterThanOrEqualTo(label);
 make.left.greaterThanOrEqualTo(label.mas_left);
 
 //如果四个边距都和父类一样这种情况
 make.edges.equalTo(superView)；
 //或者通过UIEdgeInsetsMake 设置四边边距
 make.edges.equalTo(superview).insets(UIEdgeInsetsMake(5, 10, 15, 20))
 
 //设置大小可以通过size
 make.size.equalTo(CGSizeMake(200, 100));

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

@property (nonatomic, strong) MASConstraint *widthConstraint;

self.widthConstraint.constant = 30;

[self.widthConstraint uninstall];

[contentView makeConstraints:^(MASConstraintMaker *make) {
    make.edges.equalTo(self.scrollView);
    make.width.equalTo(self.scrollView);
}];

[labelOne makeConstraints:^(MASConstraintMaker *make) {
    make.top.left.right.equalTo(contentView);
}];
[labelTwo makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(labelOne.mas_bottom);
    make.left.right.equalTo(contentView);
}];
[labelThree makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(labelTwo.mas_bottom);
    make.left.right.equalTo(contentView);
}];

[contentView makeConstraints:^(MASConstraintMaker *make) {
        make.bottom.equalTo(labelThree.bottom);
}];

make.right.greaterThanOrEqualTo(self.topView.mas_right).offset(10) 
make.right.greaterThanOrEqualTo(self.topView.mas_right).offset(-10) 
以上两种方式都不能让UILabel距离右边保持10边距。使用
make.right.lessThanOrEqualTo(self.topView.mas_right).offset(-10) 

当类似 make.right.lessThanOrEqualTo(self.topView.mas_right).offset(-10) ; 这种情况时，要分清楚，右边距防止超出是使用负值进行处理,如果期望的是距离右边边距大于10的像素，那边要使用的是lessThanOrEqualTo处理。

    [lowerButton mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(self).with.offset(10.0);
    }];

    [centerButton mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerX.equalTo(self);
    }];

    [raiseButton mas_makeConstraints:^(MASConstraintMaker *make) {
        make.right.equalTo(self).with.offset(-10);
    }];
    
    self.buttonViews = @[ raiseButton, lowerButton, centerButton ];
    
    - (void)updateConstraints {
        [self.buttonViews updateConstraints:^(MASConstraintMaker *make) {
            make.baseline.equalTo(self.mas_centerY).with.offset(self.offset);
        }];
        [super updateConstraints];
	}

testView.snp.updateConstraints {
            $0.bottom.equalTo(view).offset(-55)
}

@property(nonatomic) UIViewAutoresizing autoresizingMask;    // simple resize. default is UIViewAutoresizingNone

typedef NS_OPTIONS(NSUInteger, UIViewAutoresizing) {
    UIViewAutoresizingNone                 = 0,
    UIViewAutoresizingFlexibleLeftMargin   = 1 << 0,
    UIViewAutoresizingFlexibleWidth        = 1 << 1,
    UIViewAutoresizingFlexibleRightMargin  = 1 << 2,
    UIViewAutoresizingFlexibleTopMargin    = 1 << 3,
    UIViewAutoresizingFlexibleHeight       = 1 << 4,
    UIViewAutoresizingFlexibleBottomMargin = 1 << 5
};

button.autoresizingMask = UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleLeftMargin;
表示的是，子控件相对于父控件的顶部和右侧的距离不变。

第一步  给tableView设置估值高度 不要设置rowHeight  rowHeight返回方法也不要
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 200;

第二步

 JDGGoldDetailCell *cell = [JDGGoldDetailCell cellWithTableView:tableView];
 //MARK:自动计算行高最关键的一步  cell一定要重新布局
 [cell layoutIfNeeded];

第三步

cell的layoutSubViews中更新cell内容 
- (void)layoutSubviews {
    [super layoutSubviews];

    [self.imgview mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(self.contentView.mas_centerY);
        make.left.mas_equalTo(self.contentView.mas_left).offset(34);
        make.width.height.mas_equalTo(60);
    }];
    
    [self.titleLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.mas_equalTo(self.contentView.mas_top).offset(15);
        make.left.mas_equalTo(self.imgview.mas_right).offset(24);
        make.right.mas_equalTo(self.contentView.mas_right).offset(-20);
    }];
    
    [self.detailLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.mas_equalTo(self.titleLabel.mas_bottom).offset(13);
        make.left.mas_equalTo(self.imgview.mas_right).offset(24);
        make.right.mas_equalTo(self.contentView.mas_right).offset(-25);
        
        //MARK:自动计算行高第四步---根据大家反映,更新后的代码
        make.bottom.mas_equalTo(self.contentView.mas_bottom).offset(-10);
    }];
    
}

UIView中关于Content Hugging 和 Content Compression Resistance的方法

- (UILayoutPriority)contentHuggingPriorityForAxis:(UILayoutConstraintAxis)axis NS_AVAILABLE_IOS(6_0);

- (void)setContentHuggingPriority:(UILayoutPriority)priority forAxis:(UILayoutConstraintAxis)axis NS_AVAILABLE_IOS(6_0);

- (UILayoutPriority)contentCompressionResistancePriorityForAxis:(UILayoutConstraintAxis)axis NS_AVAILABLE_IOS(6_0);

- (void)setContentCompressionResistancePriority:(UILayoutPriority)priority forAxis:(UILayoutConstraintAxis)axis NS_AVAILABLE_IOS(6_0);

testView.snp.updateConstraints {
            $0.bottom.equalTo(view).offset(-55)
}