显示applicationDidEnterBackground前视图或闪屏（以避免活动视图截图） [英] Display a view or splash screen before applicationDidEnterBackground (to avoid active view screenshot)

问题描述

我在我的应用程序的机密信息，所以我想将它们隐藏了闪屏时，应用程序将要被转移到后台。

我做的运行iOS6的应用程序，并进一步。

我试着显示 applicationWillResignActive 的观点，但问题是，它显示启动画面，即使例如用户刷卡控制面板。我想让它显示只有当应用程序移动到后台。

我试着在 applicationDidEnterBackground 显示我的启动画面，但它需要截图之前，所以信息是在恢复过程中的动画显示。

下面的我想要什么精神：

   - （无效）applicationDidEnterBackground：（UIApplication的*）{应用
    [_window addSubview：__ splashController.view];
}
 

解决方案

我认为问题是，你在模拟器测试。在设备上，它应该很好地工作。

我测试了这一点，它的工作。添加ImageView的与你的闪屏图像时，应用程序在后台进入 -

   - （无效）applicationDidEnterBackground：（UIApplication的*）的应用
{        * UIImageView的ImageView的= [[UIImageView的页头] initWithFrame：方法self.window.bounds];        imageView.tag = 101; //给一些体面tagvalue或保持在一个自我的ImageView的引用
    // imageView.backgroundColor =的UIColor redColor]
        [ImageView的setImage：[UIImage的imageNamed：@为Default.png]]; //假设为Default.png是你的闪屏图像的名字        [UIApplication.sharedApplication.keyWindow.subviews.lastObject addSubview：ImageView的]。
}
 

和应用程序的时候回来在前台 -

   - （无效）applicationWillEnterForeground：（UIApplication的*）的应用
{
    *的UIImageView = ImageView的（UIImageView的*）[UIApplication.sharedApplication.keyWindow.subviews.lastObject viewWithTag：101] //用相同的标记值搜索
    [ImageView的removeFromSuperview]}
 

请注意 - 在模拟器（的iOS 7.0），添加的子视图是不是当你通过pressing home键两次（Cmd的+ H）检查显示，但在设备，它工作正常（如贝宝，美国银行应用程序）

编辑：（附加信息）

除了模糊/加子视图代替敏感信息/模糊如上所述，的iOS 7 为您提供忽略通过 ignoreSnapshotOnNextApplicationLaunch 的UIApplication 里面的 applicationWillResignActive 或 applicationDidEnterBackground 。

的 UIApplication.h 的

  //指明应用程序不应使用快照在下次启动，即使有一个有效的状态恢复存档。
//这应该只从国家preservation调用的方法被调用，否则将被忽略。
 - （无效）ignoreSnapshotOnNextApplicationLaunch NS_AVAILABLE_IOS（7_0）;
 

此外， allowScreenShot 标记可以探索<一个href=\"https://developer.apple.com/library/ios/featuredarticles/iPhoneConfigurationProfileRef/Introduction/Introduction.html#//apple_ref/doc/uid/TP40010206-CH1-SW13\">Restrictions有效载荷。

I have confidential informations in my app, so I would like to hide them with a splash screen when the app is about to be moved to background.

I do run the app on iOS6 and further.

I tried to display the view in applicationWillResignActive but the problem is it display the splash screen even when user swipe control panel for example. I want it to show only when the app is moved to background.

I tried to displayed my splashScreen in applicationDidEnterBackground but it takes the screenShot before so informations are displayed at restoration during the animation.

Here the spirit of what I want :

- (void)applicationDidEnterBackground:(UIApplication *)application {
    [_window addSubview:__splashController.view];
}

解决方案

I think the problem is that you are testing in simulator. On device, it should work fine.

I tested this and it worked. Add an imageview with your splash image when app enters in background -

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

        UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.window.bounds];

        imageView.tag = 101;    // Give some decent tagvalue or keep a reference of imageView in self
    //    imageView.backgroundColor = [UIColor redColor];
        [imageView setImage:[UIImage imageNamed:@"Default.png"]];   // assuming Default.png is your splash image's name

        [UIApplication.sharedApplication.keyWindow.subviews.lastObject addSubview:imageView];
}

And when app comes back in foreground -

- (void)applicationWillEnterForeground:(UIApplication *)application
{
    UIImageView *imageView = (UIImageView *)[UIApplication.sharedApplication.keyWindow.subviews.lastObject viewWithTag:101];   // search by the same tag value
    [imageView removeFromSuperview];

}

NOTE - On simulator (iOS 7.0), the added subview is not show when you check by pressing home button twice (Cmd + H), but on device it works as expected (like paypal, BofA apps)

EDIT: (Additional info)

In addition to obscuring/replacing sensitive information by adding subview / blur as explained above, iOS 7 provides you ability to ignore the screen snapshot via ignoreSnapshotOnNextApplicationLaunch of UIApplication inside applicationWillResignActive or applicationDidEnterBackground.

UIApplication.h

// Indicate the application should not use the snapshot on next launch, even if there is a valid state restoration archive.
// This should only be called from methods invoked from State Preservation, else it is ignored.
- (void)ignoreSnapshotOnNextApplicationLaunch NS_AVAILABLE_IOS(7_0);

Also, allowScreenShot flag can be explored in Restrictions Payload.

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