UIStatusBarStyle PreferredStatusBarStyle does not

问题:

In my iPhone application built with Xcode 5 for iOS 7 I set UIViewControllerBasedStatusBarAppearance=YES in info.plist, and in my ViewController I have this code:

-(UIStatusBarStyle) preferredStatusBarStyle
{
    return UIStatusBarStyleLightContent;
}

But the status bar is still black against the black background.

I know its possible to change this app-wide by setting UIViewControllerBasedStatusBarAppearance=NO in info.plist, but I actually need to alter this on a viewController by viewController basis at runtime.

回答1:

I discovered that if your ViewController is inside a navigationController then the navigationController’s navigationBar.barStyle determines the statusBarStyle.

Setting your navigationBar’s barStyle to UIBarStyleBlackTranslucent will give white status bar text (ie. UIStatusBarStyleLightContent), and UIBarStyleDefault will give black status bar text (ie. UIStatusBarStyleDefault).

Note that this applies even if you totally change the navigationBar’s color via its barTintColor.

回答2:

OK, here's the trick. You do have to add the key "View controller-based status bar" and set the value to No.

This is counter to what it appears the meaning of this key is, but even if you set the value to No, you can still change the appearance of the status bar, and whether it shows or not in any view controller. So it acts like "Yes" but set it to "No"!

Now I can get the status bar white or dark.

回答3:

For preferredStatusBarStyle() to work within UINavigationController and UITabBarController I add the following code, which will get the preferred status bar style from the currently visible view controller.

extension UITabBarController {
    public override func childViewControllerForStatusBarStyle() -> UIViewController? {
        return selectedViewController
    }
}

extension UINavigationController {
    public override func childViewControllerForStatusBarStyle() -> UIViewController? {
        return visibleViewController
    }
}

For Swift 3 those are not methods but properties:

extension UITabBarController {
    open override var childViewControllerForStatusBarStyle: UIViewController? {
        return selectedViewController
    }
}

extension UINavigationController {
    open override var childViewControllerForStatusBarStyle: UIViewController? {
        return visibleViewController
    }
}

The Swift 4.2 properties have been renamed:

extension UITabBarController {
   open override var childForStatusBarStyle: UIViewController? {
        return selectedViewController
    }
}

extension UINavigationController {
   open override var childForStatusBarStyle: UIViewController? {
        return visibleViewController
    }
}

Usage

class ViewController: UIViewController {

    // This will be called every time the ViewController appears
    // Works great for pushing & popping
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }

}

回答4:

I may be coming to this a bit late, but incase anyone else is looking for a working and verified app wide solution.

@mxcl is correct in describing why this is happening. In order to correct it, we simply create an extension (or category in obj-c) that overrides the preferredSatusBarStyle() method of UINavigationController. Here is an example in Swift:

extension UINavigationController {
    public override func preferredStatusBarStyle() -> UIStatusBarStyle {
        if let rootViewController = self.viewControllers.first {
            return rootViewController.preferredStatusBarStyle()
        }
        return super.preferredStatusBarStyle()
    }
}

This code simply extracts the first view controller (the root view controller) and unwraps it (in obj-c just check that it is not nil). If the unwrap is successful (not nil) then we grab the rootViewControllers preferredStatusBarStyle. Otherwise we just return the default.

Hope this helps anyone who might need it.

回答5:

To provide more detail into the accepted answer, put the following line in your app delegate's didFinishLaunchingWithOptions: method:

[UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleLightContent;

Then, in your Info.plist, add View controller-based status bar appearance and set it to NO.

I believe that's how it should be done, NOT from the navigation controller, if you want the same status bar color for the entire app. You might have screens that are not necessarily embedded in a UINavigationController, or a different UINavigationController subclass somewhere else, and other things.

EDIT: You can also do it without typing any code: https://stackoverflow.com/a/18732865/855680

回答6:

In viewDidLoad just write this

[self setNeedsStatusBarAppearanceUpdate];

just do that and it will work

can u please try this

Set UIViewControllerBasedStatusBarAppearance to NO.
Call [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

One more thing i have seen in your question that you have wrote the method like this

 -(void)UIStatusBarStyle PreferredStatusBarStyle ()
        {
            return UIStatusBarStyle.LightContent;
        }

but it should be like this

-(UIStatusBarStyle)preferredStatusBarStyle{ 
    return UIStatusBarStyleLightContent; 
} 

回答7:

Here is how I solved it. Usually the navigationController or tabBarController are the ones deciding the appearance of the status bar (hidden, color, etc).

So I ended up subclassing the navigation controller and overriding preferredStatusBarStyle. if the current visible ViewContorller implements StatusBarStyleHandler I ask for the value to be used as the style, if it doesn't I just return a default value.

The way you trigger an update of the status bar appearance is by calling setNeedsStatusBarAppearanceUpdate which triggers preferredStatusBarStyle again and updates UI according to what the method returns

public protocol StatusBarStyleHandler {
    var preferredStatusBarStyle: UIStatusBarStyle { get }
}

public class CustomNavigationCotnroller: UINavigationController {

    public override var preferredStatusBarStyle: UIStatusBarStyle {
        if let statusBarHandler = visibleViewController as? StatusBarStyleHandler {
            return statusBarHandler.preferredStatusBarStyle
        }

        return .default
    }
}

Then usage

public class SomeController: UIViewController, StatusBarStyleHandler {

    private var statusBarToggle = true

    // just a sample for toggling the status bar style each time method is called
    private func toggleStatusBarColor() {
        statusBarToggle = !statusBarToggle
        setNeedsStatusBarAppearanceUpdate()
    }

    public override var preferredStatusBarStyle: UIStatusBarStyle {
        return statusBarToggle ? .lightContent : .default
    }
}

回答8:

Even with all the answers here i still didn't find the exact solution for me, but started with the answer from Daniel. What I ended up with was:

override var preferredStatusBarStyle: UIStatusBarStyle {
     return visibleViewController?.preferredStatusBarStyle ?? .lightContent
}

in navigation controllers (similar for tab, just selectedViewController). And then it will respect the:

override var preferredStatusBarStyle: UIStatusBarStyle {
     return .lightContent
}

In each view controller unless you set it otherwise. I dont need to call setNeedsStatusBarAppearanceUpdate() anywhere, it just updates when you arrive at each view controller.

回答9:

1) One setting for whole project:

If available, remove UIViewControllerBasedStatusBarAppearance key-value pair from your info.plist, or set NO without removing it. If it's not available in your info.plist, do nothing. Default is NO for this property.

Add below code to your AppDelegate.m:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
}

2) Different settings for different View Controllers:

Add UIViewControllerBasedStatusBarAppearance key-value pair to your info.plist and set it to YES.

If your View Controller is not embed in to Navigation Controller. Let's say MyViewController. just add code below to your MyViewController.m file. If your View Controller is embed in to Navigation Controller, create a new Cocoa Touch Class and make it subclass of UINavigationController. Let's say MyNC. Select Navigation Controller View on your Storyboard, at right pane; Utilities -> Identity Inspector -> Custom Class -> Class, type "MyNC". After linking Storyboard View with your "MyNC" Cocoa Touch Class, add code below to your MyNC.m:

- (BOOL)prefersStatusBarHidden {
    return NO;
}

-(UIStatusBarStyle)preferredStatusBarStyle {
    return UIStatusBarStyleLightContent;
}

回答10:

Swift 4.2

extension UITabBarController {
    open override var childForStatusBarStyle: UIViewController? {
        return selectedViewController
    }
}

extension UINavigationController {
    open override var childForStatusBarStyle: UIViewController? {
        return visibleViewController
    }
}

回答11:

If in case you wanted to hide the statusBar during splashScreen but wanted to change the style to light content (StatusBarInitiallyHidden on Plist has to be NO to hide statusBar on splash), you can add this to appDelegate's didFinishLaunchingWithOptions method to change to lightContent.

[[UIApplication sharedApplication]setStatusBarHidden:NO withAnimation:UIStatusBarAnimationSlide];
[[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent];

回答12:

swift example

in AppDelegate.swift

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {
    UIApplication.sharedApplication().statusBarStyle = UIStatusBarStyle.LightContent;

    return true
}

in info.plist set View controller-based status bar appearance: NO

回答13:

If you're using NavigationController, you can subclass NavigationController so that it consults its child view controller

// MyCustomNavigationController

- (NSUInteger)supportedInterfaceOrientations {
    UIViewController *viewControllerToAsk = [self findChildVC];
    return [viewControllerToAsk supportedInterfaceOrientations];
}

- (BOOL)shouldAutorotate {
    UIViewController *viewControllerToAsk = [self findChildVC];
    return [viewControllerToAsk shouldAutorotate];
}

- (UIStatusBarStyle)preferredStatusBarStyle {
    UIViewController *viewControllerToAsk = [self findChildVC];
    return [viewControllerToAsk preferredStatusBarStyle];
}

- (UIViewController *)findChildVC {
    return self.viewControllers.firstObject;
}

回答14:

You can set the status bar style. It will resembles the status bar like IOS 6 and below.
Paste this methods in your view controller

-(UIStatusBarStyle)preferredStatusBarStyle{
    return UIStatusBarStyleBlackOpaque;
}

and call this method from view did load like this

if([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0f)
    {
       [self setNeedsStatusBarAppearanceUpdate];
    }

回答15:

I just want to add a note for a specific case I faced. I had another UIWindow in my app to display a chat face to be floating all over my app all the time. Doing this caused none of the solution above to work, and I am not really sure why! All what I have noticed is that my ViewController in the new UIWindow was the reason for that! And if I wanted to change the status bar style I have to do it in that view controller of the new UIWindow.

This note might help others who have a similar structure! So basically you can apply the solutions mentioned above in the ViewController of the new UIWindow.

Again this a specific case.

Thanks

回答16:

For swift 3, in your UIViewController:

override var preferredStatusBarStyle : UIStatusBarStyle { return UIStatusBarStyle.lightContent }