我遵循这个线程重写-preferredStatusBarStyle,但它没有被调用。 有什么选项我可以改变来启用它吗?(我在我的项目中使用xib。)
当前回答
这是我解决这个问题的方法。
定义一个名为AGViewControllerAppearance的协议。
AGViewControllerAppearance.h
#import <Foundation/Foundation.h>
@protocol AGViewControllerAppearance <NSObject>
@optional
- (BOOL)showsStatusBar;
- (BOOL)animatesStatusBarVisibility;
- (UIStatusBarStyle)preferredStatusBarStyle;
- (UIStatusBarAnimation)prefferedStatusBarAnimation;
@end
在UIViewController上定义一个名为Upgrade的类别。
UIViewController+Upgrade.h
#import <UIKit/UIKit.h>
@interface UIViewController (Upgrade)
//
// Replacements
//
- (void)upgradedViewWillAppear:(BOOL)animated;
@end
UIViewController+Upgrade.m
#import "UIViewController+Upgrade.h"
#import <objc/runtime.h>
#import "AGViewControllerAppearance.h" // This is the appearance protocol
@implementation UIViewController (Upgrade)
+ (void)load
{
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wselector"
Method viewWillAppear = class_getInstanceMethod(self, @selector(viewWillAppear:));
#pragma clang diagnostic pop
Method upgradedViewWillAppear = class_getInstanceMethod(self, @selector(upgradedViewWillAppear:));
method_exchangeImplementations(viewWillAppear, upgradedViewWillAppear);
}
#pragma mark - Implementation
- (void)upgradedViewWillAppear:(BOOL)animated
{
//
// Call the original message (it may be a little confusing that we're
// calling the 'same' method, but we're actually calling the original one :) )
//
[self upgradedViewWillAppear:animated];
//
// Implementation
//
if ([self conformsToProtocol:@protocol(AGViewControllerAppearance)])
{
UIViewController <AGViewControllerAppearance> *viewControllerConformingToAppearance =
(UIViewController <AGViewControllerAppearance> *)self;
//
// Status bar
//
if ([viewControllerConformingToAppearance respondsToSelector:@selector(preferredStatusBarStyle)])
{
BOOL shouldAnimate = YES;
if ([viewControllerConformingToAppearance respondsToSelector:@selector(animatesStatusBarVisibility)])
{
shouldAnimate = [viewControllerConformingToAppearance animatesStatusBarVisibility];
}
[[UIApplication sharedApplication] setStatusBarStyle:[viewControllerConformingToAppearance preferredStatusBarStyle]
animated:shouldAnimate];
}
if ([viewControllerConformingToAppearance respondsToSelector:@selector(showsStatusBar)])
{
UIStatusBarAnimation animation = UIStatusBarAnimationSlide;
if ([viewControllerConformingToAppearance respondsToSelector:@selector(prefferedStatusBarAnimation)])
{
animation = [viewControllerConformingToAppearance prefferedStatusBarAnimation];
}
[[UIApplication sharedApplication] setStatusBarHidden:(! [viewControllerConformingToAppearance showsStatusBar])
withAnimation:animation];
}
}
}
@end
现在,是时候说你的视图控制器正在实现AGViewControllerAppearance协议。
例子:
@interface XYSampleViewController () <AGViewControllerAppearance>
... the rest of the interface
@end
当然,你可以实现其余的方法(showsStatusBar, animatesStatusBarVisibility, prefereredstatusbaranimation)从协议和UIViewController+升级将做适当的 基于它们提供的值进行定制。
其他回答
可能的根本原因
我也遇到了同样的问题,我发现这是因为我没有在我的应用程序窗口中设置根视图控制器。
我在UIViewController中实现了preferredStatusBarStyle,在UITabBarController中使用,它控制了屏幕上视图的外观。
当我设置根视图控制器指向这个UITabBarController时,状态栏的变化开始正确工作,正如预期的那样(preferredStatusBarStyle方法正在被调用)。
(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
... // other view controller loading/setup code
self.window.rootViewController = rootTabBarController;
[self.window makeKeyAndVisible];
return YES;
}
替代方法(在iOS 9中已弃用)
另外,你也可以在每个视图控制器中调用以下方法之一,这取决于它的背景颜色,而不是必须使用setNeedsStatusBarAppearanceUpdate:
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
or
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];
注意,如果你使用这个方法,你还需要在plist文件中将UIViewControllerBasedStatusBarAppearance设置为NO。
Swift 4.2及以上版本
正如所选答案中提到的,根本原因是检查您的窗口根视图控制器对象。
流结构的可能情况
Custom UIViewController object is window root view controller Your window root view controller is a UIViewController object and it further adds or removes navigation controller or tabController based on your application flow. This kind of flow is usually used if your app has pre login flow on navigation stack without tabs and post login flow with tabs and possibly every tab further holds navigation controller. TabBarController object is window root view controller This is the flow where window root view controller is tabBarController possibly every tab further holds navigation controller. NavigationController object is window root view controller This is the flow where window root view controller is navigationController. I am not sure if there is any possibility to add tab bar controller or new navigation controller in an existing navigation controller. But if there is such case, we need to pass the status bar style control to the next container. So, I added the same check in UINavigationController extension to find childForStatusBarStyle
使用以下扩展,它处理所有上述场景-
extension UITabBarController {
open override var childForStatusBarStyle: UIViewController? {
return selectedViewController?.childForStatusBarStyle ?? selectedViewController
}
}
extension UINavigationController {
open override var childForStatusBarStyle: UIViewController? {
return topViewController?.childForStatusBarStyle ?? topViewController
}
}
extension AppRootViewController {
open override var preferredStatusBarStyle: UIStatusBarStyle {
return children.first { $0.childForStatusBarStyle != nil }?.childForStatusBarStyle?.preferredStatusBarStyle ?? .default
}
}
在info中你不需要UIViewControllerBasedStatusBarAppearance键。Plist默认为true
对于更复杂的流程,需要考虑的要点
In case you present new flow modally, it detaches from the existing status bar style flow. So, suppose you are presenting a NewFlowUIViewController and then add new navigation or tabBar controller to NewFlowUIViewController, then add extension of NewFlowUIViewController as well to manage further view controller's status bar style. In case you set modalPresentationStyle other than fullScreen while presenting modally, you must set modalPresentationCapturesStatusBarAppearance to true so that presented view controller must receive status bar appearance control.
Hippo的回答:如果你正在使用UINavigationController,那么最好添加一个类别:
// UINavigationController+StatusBarStyle.h:
@interface UINavigationController (StatusBarStyle)
@end
// UINavigationController+StatusBarStyle.m:
@implementation UINavigationController (StatusBarStyle)
- (UIStatusBarStyle)preferredStatusBarStyle
{
//also you may add any fancy condition-based code here
return UIStatusBarStyleLightContent;
}
@end
这种解决方案可能比切换到即将被弃用的行为要好。
Swift 3 iOS 10解决方案:
override var preferredStatusBarStyle: UIStatusBarStyle {
return .lightContent
}
在UINavigationController上,preferredStatusBarStyle不会被调用,因为它的topViewController优先于self。所以,要在UINavigationController上调用preferredStatusBarStyle,你需要改变它的childForStatusBarStyle (Swift) / childViewControllerForStatusBarStyle (ObjC)。
建议
重写你类中的UINavigationController:
class MyRootNavigationController: UINavigationController {
override var preferredStatusBarStyle: UIStatusBarStyle {
return .lightContent
}
override var childForStatusBarStyle: UIViewController? {
return nil
}
}
非推荐替代方案
要为所有UINavigationController做这件事,你可以在一个扩展中覆盖(警告:它会影响UIDocumentPickerViewController, UIImagePickerController等),但你可能不应该根据Swift文档这样做:
extension UINavigationController {
open override var preferredStatusBarStyle: UIStatusBarStyle {
return .lightContent
}
open override var childForStatusBarStyle: UIViewController? {
return nil
}
}
推荐文章
- 我如何在我的iOS应用程序中每n分钟得到一个后台位置更新?
- 如何使用iOS创建GUID/UUID
- 禁用所呈现视图控制器的交互式撤销
- 点击按钮时如何打开手机设置?
- 如何使用UIVisualEffectView来模糊图像?
- 如何修复UITableView分隔符在iOS 7?
- 故事板中的自定义单元格行高设置没有响应
- 在Swift中使用自定义消息抛出错误/异常的最简单方法?
- 如何在Swift中获得唯一的设备ID ?
- 复制文本到剪贴板与iOS
- 在Swift中根据字符串计算UILabel的大小
- 如何调用手势点击在UIView编程在迅速
- 我如何隐藏在一个Swift iOS应用程序的状态栏?
- 在iPad上使用iOS 8正确呈现UIAlertController
- 尝试将一个非属性列表对象设置为NSUserDefaults