金融类app防止信息在后台中被一些恶意截屏软件进行截屏，对进入后台的app做模糊处理

- (void)applicationWillResignActive:(UIApplication *)application {

    //进入后台盖上view，实现模糊效果

    

    UIView* view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];

    

    UIImageView *imageV = [[UIImageView alloc] initWithFrame:[UIScreen mainScreen].bounds];

    //获取当前视图控制器

    UIViewController *vc = [self getCurrentVC];

    //截取当前视图为图片

    imageV.image = [self snapshot:vc.view];

    

    //添加毛玻璃效果

    UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];

    UIVisualEffectView *effectview = [[UIVisualEffectView alloc] initWithEffect:blur];

    effectview.frame = [UIScreen mainScreen].bounds;

    [imageV addSubview:effectview];

    view.tag = 1111;

    [view addSubview:imageV];

    

    [self.window addSubview:view];

}

//获取当前控制器

- (UIViewController *)getCurrentVC {

    

    UIWindow *window = [[UIApplication sharedApplication].windows firstObject];

    if (!window) {

        return nil;

    }

    UIView *tempView;

    for (UIView *subview in window.subviews) {

        if ([[subview.classForCoder description] isEqualToString:@"UILayoutContainerView"]) {

            tempView = subview;

            break;

        }

    }

    if (!tempView) {

        tempView = [window.subviews lastObject];

    }

    

    id nextResponder = [tempView nextResponder];

    while (![nextResponder isKindOfClass:[UIViewController class]] || [nextResponder isKindOfClass:[UINavigationController class]] || [nextResponder isKindOfClass:[UITabBarController class]]) {

        tempView =  [tempView.subviews firstObject];

        

        if (!tempView) {

            return nil;

        }

        nextResponder = [tempView nextResponder];

    }

    return  (UIViewController *)nextResponder;

}

//截取当前视图为图片

- (UIImage *)snapshot:(UIView *)view

{

    

    UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0);

    

    [view drawViewHierarchyInRect:view.bounds afterScreenUpdates:YES];

    

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    

    UIGraphicsEndImageContext();

    return image;

    

}

同时在app进入前台中需要把模糊界面去除

- (void)applicationDidBecomeActive:(UIApplication *)application {

    UIView *view = (UIView *)[self.window viewWithTag:1111];

    [view removeFromSuperview];

}