#import "FirstViewController.h"

@interface FirstViewController ()

- (IBAction)axisChange:(UISwitch *)sender;

@property (weak, nonatomic) IBOutlet UIStackView *imageStackView;

@implementation FirstViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

- (IBAction)axisChange:(UISwitch *)sender

{

[UIView animateWithDuration:0.25 animations:^{

[self updateConstraintsForAxis];

}];

}

- (void)updateConstraintsForAxis

{

// 在水平、垂直堆栈视图间切换

if (self.imageStackView.axis == UILayoutConstraintAxisHorizontal)

{

self.imageStackView.axis = UILayoutConstraintAxisVertical;

}

else

{

self.imageStackView.axis = UILayoutConstraintAxisHorizontal;

}

}