IOS第四天(1:图片的方法和缩小,遮罩层)

@interface HMViewController ()

@property (nonatomic, strong) UIButton *cover;   //阴影

@end

@implementation HMViewController

//懒加载,阴影
- (UIButton *)cover
{
    if (_cover == nil) {
        _cover = [[UIButton alloc] initWithFrame:self.view.bounds];
        _cover.backgroundColor = [UIColor colorWithWhite:0.0 alpha:0.5];
        [self.view addSubview:_cover];
        _cover.alpha = 0.0;

        [_cover addTarget:self action:@selector(bigImage) forControlEvents:UIControlEventTouchUpInside];
    }
    return _cover;
}

/** 调整状态栏颜色 */
/**
 UIStatusBarStyleDefault      黑色状态栏
 UIStatusBarStyleLightContent 亮色状态栏
 */
- (UIStatusBarStyle)preferredStatusBarStyle
{
    return UIStatusBarStyleLightContent;
}

/**
 *  大图小图显示切换
 */
- (IBAction)bigImage
{
    // 如果没有放大，就放大，否则就缩小
    // 通过蒙板的alpha来判断按钮是否已经被放大
    if (self.cover.alpha == 0.0) { // 放大
        // 2. 将图像按钮弄到最前面
        // bringSubviewToFront将子视图前置
        [self.view bringSubviewToFront:self.iconButton];

        // 3. 动画放大图像按钮
        CGFloat w = self.view.bounds.size.width;
        CGFloat h = w;
        CGFloat y = (self.view.bounds.size.height - h) * 0.5;

        [UIView animateWithDuration:1.0f animations:^{
            self.iconButton.frame = CGRectMake(, y, w, h);
            self.cover.alpha = 1.0;
        }];
    } else { // 缩小
        [UIView animateWithDuration:1.0 animations:^{
            // 将图像恢复初始位置
            self.iconButton.frame = CGRectMake(, , , );
            self.cover.alpha = 0.0;
        }];
    }
}
@end