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(0, 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(85, 85, 150, 150);

            self.cover.alpha = 0.0;

        }];

    }

}

@end