图像变换与按钮交互

通过修改按钮的transform属性实现图像的动态效果。

缩放操作

- (IBAction)scaleButton:(UIButton *)btn {
    CGRect frame = self.imageView.frame;
    CGFloat factor = btn.isSelected ? 1.2f : 0.8f;
    frame.size.width *= factor;
    frame.size.height *= factor;
    
    [UIView animateWithDuration:0.5 animations:^{
        self.imageView.frame = frame;
    }];
}

位移变换

CGAffineTransform move = CGAffineTransformTranslate(self.imageView.transform, 0, -30);
self.imageView.transform = move;
NSLog(@"%@", NSStringFromCGAffineTransform(self.imageView.transform));

旋转效果

CGFloat rotation = btn.isSelected ? -M_PI_4 : M_PI_4;
self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, rotation);

动态按钮创建

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 创建系统按钮
    UIButton *sysBtn = [UIButton buttonWithType:UIButtonTypeSystem];
    sysBtn.frame = CGRectMake(20, 20, 100, 40);
    [sysBtn setTitle:@"点击" forState:UIControlStateNormal];
    [self.view addSubview:sysBtn];
    
    // 创建自定义按钮
    UIButton *customBtn = [[UIButton alloc] initWithFrame:CGRectMake(150, 20, 100, 40)];
    customBtn.backgroundColor = [UIColor lightGrayColor];
    [customBtn setBackgroundImage:[UIImage imageNamed:@"btn_normal"] forState:UIControlStateNormal];
    [customBtn setBackgroundImage:[UIImage imageNamed:@"btn_pressed"] forState:UIControlStateHighlighted];
    [self.view addSubview:customBtn];
}

图像切换界面

实现左右按钮控制图片浏览功能。

- (NSArray *)imageData {
    if (!_imageData) {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"Gallery" ofType:@"plist"];
        _imageData = [NSArray arrayWithContentsOfFile:path];
    }
    return _imageData;
}

- (void)updateDisplay {
    NSDictionary *item = self.imageData[self.currentIndex];
    self.imageView.image = [UIImage imageNamed:item[@"imageName"]];
    self.titleLabel.text = item[@"description"];
    
    self.leftBtn.enabled = self.currentIndex > 0;
    self.rightBtn.enabled = self.currentIndex < self.imageData.count - 1;
}

内存管理实践

强引用与弱引用的区别：

• 强引用：__strong Person *person = [[Person alloc] init];
• 弱引用：__weak Person *weakSelf = person;

自动释放机制确保无强引用对象被回收。

Tom猫动画实现

- (IBAction)playAnimation:(UIButton *)sender {
    if (self.catImageView.isAnimating) return;
    
    NSMutableArray *frames = [NSMutableArray array];
    for (int i = 0; i < 25; i++) {
        NSString *filename = [NSString stringWithFormat:@"cat_%02d.jpg", i];
        NSString *path = [[NSBundle mainBundle] pathForResource:filename ofType:nil];
        [frames addObject:[UIImage imageWithContentsOfFile:path]];
    }
    
    self.catImageView.animationImages = frames;
    self.catImageView.animationDuration = 2.0;
    [self.catImageView startAnimating];
    
    [self performSelector:@selector(clearAnimation) withObject:nil afterDelay:self.catImageView.animationDuration];
}

- (void)clearAnimation {
    self.catImageView.animationImages = nil;
}