Masonry详解

- (void)viewDidLoad {

    [super viewDidLoad];

    //1.view1 居中显示

    UIView *view1 = [[UIView alloc]init];

    view1.backgroundColor = [UIColor redColor];

    [self.view addSubview:view1];

    [view1 mas_makeConstraints:^(MASConstraintMaker *make) {

        make.center.equalTo(self.view);  //居中

        make.size.mas_equalTo(CGSizeMake(300, 300));  //设置宽高

        //make.size.equalTo(@100);    //设置size

        //make.size.mas_equalTo(@100);

    }];

    //2.view2  在view1的正中间

    UIView *view2 = [UIView new];

    view2.backgroundColor = [UIColor blackColor];

    [view1 addSubview:view2];

    [view2 mas_makeConstraints:^(MASConstraintMaker *make) {

       // make.top.left.bottom.and.right.equalTo(view1).with.insets(UIEdgeInsetsMake(10, 10, 10, 10));

等价于:

//         make.top.equalTo(view1).with.offset(10);

//         make.left.equalTo(view1).with.offset(10);

//         make.bottom.equalTo(view1).with.offset(-10);

//         make.right.equalTo(view1).with.offset(-10);

//

也等价于:

        //设置四边缩进20

        make.edges.equalTo(view1).with.insets(UIEdgeInsetsMake(20, 20, 20, 20));

//        make.size.width.equalTo(@200);

//        make.size.height.equalTo(@200);

//        

    }];

注意点:

    /*

     mas_makeConstraints 只负责新增约束 Autolayout不能同时存在两条针对于同一对象的约束 否则会报错

     mas_updateConstraints 针对上面的情况 会更新在block中出现的约束 不会导致出现两个相同约束的情况

     mas_remakeConstraints 则会清除之前的所有约束 仅保留最新的约束

    [view1 mas_makeConstraints:^(MASConstraintMaker *make) {

    }];

    [view1 mas_remakeConstraints:^(MASConstraintMaker *make) {

    }];

    [view1 mas_updateConstraints:^(MASConstraintMaker *make) {

    }];

     */

    //3.view3与view1 在同一列

    UIView *view3 = [UIView new];

    view3.backgroundColor = [UIColor greenColor];

    [self.view addSubview:view3];

    [view3 mas_makeConstraints:^(MASConstraintMaker *make) {

        make.size.mas_equalTo(CGSizeMake(100, 100));

        make.centerX.equalTo(view1);   //设置水平居中

        make.top.equalTo(view1.mas_bottom).with.offset(20);  //与上view的垂直间隔

    }];

}