这可能是一个压倒性的问题，如果你使用自动布局，因为你不能直接操作帧。有一个简单的解决方案，不需要太多的工作。

我最终在一个实用工具类中编写了一个实用方法，并从所有视图控制器的viewDidLayoutSubviews方法中调用它。

+ (void)addStatusBarIfiOS7:(UIViewController *)vc
    {
        if (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_6_1) {
            CGRect viewFrame = vc.view.frame;
            if(viewFrame.origin.y == 20) {
                //If the view's y origin is already 20 then don't move it down.
                return;
            }
            viewFrame.origin.y+=20.0;
            viewFrame.size.height-= 20.0;
            vc.view.frame = viewFrame;
            [vc.view layoutIfNeeded];
        }
    }

重写视图控制器中的viewDidLayoutSubviews方法，在那里你想要状态栏。它会让你通过自动布局的负担。

- (void)viewDidLayoutSubviews
{
    [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent];
    [super viewDidLayoutSubviews];
    [MyUtilityClass addStatusBarIfiOS7:self];
}

对于Archy Holt的回答，有一个小的选择，更简单一点:

a.在info.plist中设置“UIViewControllerBasedStatusBarAppearance”为“NO”

b.在AppDelegate的应用程序didFinishLaunchingWithOptions:中调用:

if ([[UIDevice currentDevice].systemVersion floatValue] < 7)
{
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
}
else
{
    // handling statusBar (iOS7)
    application.statusBarStyle = UIStatusBarStyleLightContent;
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].applicationFrame];
    self.window.clipsToBounds = YES;

    // handling screen rotations for statusBar (iOS7)
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationDidChangeStatusBarOrientationNotification:) name:UIApplicationDidChangeStatusBarOrientationNotification object:nil];
}

并添加方法:

- (void)applicationDidChangeStatusBarOrientationNotification:(NSNotification *)notification
{
    // handling statusBar (iOS7)
    self.window.frame = [UIScreen mainScreen].applicationFrame;
}

你也可以考虑子类化UIWindow来处理UIApplicationDidChangeStatusBarOrientationNotification本身。

这是我写的一篇博客文章的交叉发布，但这里是关于iOS 7上的状态栏、导航栏和容器视图控制器的完整概述:

There is no way to preserve the iOS 6 style status bar layout. The status bar will always overlap your application on iOS 7 Do not confuse status bar appearance with status bar layout. The appearance (light or default) does not affect how the status bar is laid out (frame/height/overlap). It is important to note as well that the system status bar no longer has any background color. When the API refers to UIStatusBarStyleLightContent, they mean white text on a clear background. UIStatusBarStyleDefault is black text on a clear background. Status bar appearance is controlled along one of two mutually-exclusive basis paths: you can either set them programmatically in the traditional manner, or UIKit will update the appearance for you based on some new properties of UIViewController. The latter option is on by default. Check your app’s plist value for “ViewController-Based Status Bar Appearance” to see which one you’re using. If you set this value to YES, every top-level view controller in your app (other than a standard UIKit container view controller) needs to override preferredStatusBarStyle, returning either the default or the light style. If you edit the plist value to NO, then you can manage the status bar appearance using the familiar UIApplication methods. UINavigationController will alter the height of its UINavigationBar to either 44 points or 64 points, depending on a rather strange and undocumented set of constraints. If the UINavigationController detects that the top of its view’s frame is visually contiguous with its UIWindow’s top, then it draws its navigation bar with a height of 64 points. If its view’s top is not contiguous with the UIWindow’s top (even if off by only one point), then it draws its navigation bar in the “traditional” way with a height of 44 points. This logic is performed by UINavigationController even if it is several children down inside the view controller hierarchy of your application. There is no way to prevent this behavior. If you supply a custom navigation bar background image that is only 44 points (88 pixels) tall, and the UINavigationController’s view’s bounds matches the UIWindow’s bounds (as discussed in #4), the UINavigationController will draw your image in the frame (0,20,320,44), leaving 20 points of opaque black space above your custom image. This may confuse you into thinking you are a clever developer who bypassed rule #1, but you are mistaken. The navigation bar is still 64 points tall. Embedding a UINavigationController in a slide-to-reveal style view hierarchy makes this abundantly clear. Beware of the confusingly-named edgesForExtendedLayout property of UIViewController. Adjusting edgesForExtendedLayout does nothing in most cases. The only way UIKit uses this property is if you add a view controller to a UINavigationController, then the UINavigationController uses edgesForExtendedLayout to determine whether or not its child view controller should be visible underneath the navigation bar / status bar area. Setting edgesForExtendedLayout on the UINavigationController itself does nothing to alter whether or not the UINavigationController has a 44 or 64 point high navigation bar area. See #4 for that logic. Similar layout logic applies to the bottom of your view when using a toolbar or UITabBarController. If all you are trying to do is prevent your custom child view controller from underlapping the navigation bar when inside a UINavigationController, then set edgesForExtendedLayout to UIRectEdgeNone (or at least a mask that excludes UIRectEdgeTop). Set this value as early as possible in the life cycle of your view controller. UINavigationController and UITabBarController will also try to pad the contentInsets of table views and collection views in its subview hierarchy. It does this in a manner similar to the status bar logic from #4. There is a programmatic way of preventing this, by setting automaticallyAdjustsScrollViewInsets to NO for your table views and collection views (it defaults to YES). This posed some serious problems for Whisper and Riposte, since we use contentInset adjustments to control the layout of table views in response to toolbar and keyboard movements. To reiterate: there is no way to return to iOS 6 style status bar layout logic. In order to approximate this, you have to move all the view controllers of your app into a container view that is offset by 20 points from the top of the screen, leaving an intentionally black view behind the status bar to simulate the old appearance. This is the method we ended up using in Riposte and Whisper. Apple is pushing very hard to ensure that you don’t try to do #9. They want us to redesign all our apps to underlap the status bar. There are many cogent arguments, however, for both user experience and technical reasons, why this is not always a good idea. You should do what is best for your users and not simply follow the whimsy of the platform.

如果你不希望你的视图控制器被状态栏(和导航栏)重叠，在Xcode 5的Interface Builder中取消选中“在顶部栏下扩展边缘”框。

解决方案:

通过重写方法在你的视图控制器或rootviewcontroller中设置它:

-(BOOL) prefersStatusBarHidden
    {
        return YES;
    }

为了继续使用setStatusBarHidden:我使用这个类别:

@interface UIApplication (StatusBar)

-(void)setIOS7StatusBarHidden:(BOOL)statusBarHidden;

@end

@implementation UIApplication (StatusBar)

-(void)setIOS7StatusBarHidden:(BOOL)statusBarHidden{
    if (!IOS7) {
        [self setStatusBarHidden:statusBarHidden];
        return;
     }

    if ([self isStatusBarHidden] == statusBarHidden) {
        return;
    }

    [self setStatusBarHidden:statusBarHidden];
    [self keyWindow].clipsToBounds = YES;
    CGFloat offset = statusBarHidden ? 0 : 20;
    [self keyWindow].frame =  CGRectMake(0,offset,[self keyWindow].frame.size.width,[self keyWindow].frame.size.height-offset);
    [self keyWindow].bounds = CGRectMake(0, offset, [self keyWindow].frame.size.width,[self keyWindow].frame.size.height);
}

@end