#import "ThirdViewController.h"

@interface ThirdViewController ()

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

- (IBAction)addStar:(UIButton *)sender;

- (IBAction)removeStar:(UIButton *)sender;

@implementation ThirdViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view.

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

- (IBAction)addStar:(UIButton *)sender

{

UIImageView *filledStarView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"filledStar"]];

// 添加视图到堆栈视图

[self.horizontalStackView addArrangedSubview:filledStarView];

filledStarView.contentMode = UIViewContentModeScaleAspectFit;

[UIView animateWithDuration:0.25 animations:^{

[self.horizontalStackView layoutIfNeeded];

}];

}

- (IBAction)removeStar:(UIButton *)sender

{

UIView *filledView = self.horizontalStackView.arrangedSubviews.lastObject;

// 如果视图存在，移除视图

if (filledView)

{

[filledView removeFromSuperview]; // 会自动从arrangedSubviews移除

[UIView animateWithDuration:0.25 animations:^{

[self.horizontalStackView layoutIfNeeded];

}];

}

}