- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIButton *button = [UIButton buttonWithType:UIButtonTypeContactAdd];
    button.frame = CGRectMake(0, 0, 50, 50);
    button.tag = 1001;
    [button addTarget:self action:@selector(clickButton:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];
    
    UIView *sv2 = [[UIView alloc] init];
    sv2.backgroundColor = [UIColor redColor];
    
    UIView *sv3 = [[UIView alloc] init];
    sv3.backgroundColor = [UIColor greenColor];
    
    UIView *sv4 = [[UIView alloc] init];
    sv4.backgroundColor = [UIColor blueColor];
    
    UIView *sv = self.view;
    
    [sv addSubview:sv2];
    [sv addSubview:sv3];
    [sv addSubview:sv4];

    
    int padding1 = 10;
    
    [sv2 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(sv.mas_centerY);
        make.left.equalTo(sv.mas_left).with.offset(padding1);
        make.right.equalTo(sv3.mas_left).with.offset(-padding1);
        self.constraint = make.height.equalTo(@150);
        make.width.equalTo(sv3);
    }];
    
    [sv3 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(sv.mas_centerY);
        make.left.equalTo(sv2.mas_right).with.offset(padding1);
        make.right.equalTo(sv4.mas_left).with.offset(-padding1);
        make.height.equalTo(@150);
        make.width.equalTo(sv4);
    }];
    
    [sv4 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(sv.mas_centerY);
        make.left.equalTo(sv3.mas_right).with.offset(padding1);
        make.right.equalTo(sv.mas_right).with.offset(-padding1);
        make.height.equalTo(@150);
        make.width.equalTo(sv2);
    }];
    
}

- (void)clickButton:(UIButton *)sender {
    
    if (sender.tag == 1001) {
        sender.tag = 1002;
        self.constraint.equalTo(@50);
        
        
    }else if (sender.tag == 1002) {
        sender.tag = 1001;
        self.constraint.equalTo(@150);
    }
    
}