如何隐藏iPhone X的home指示灯在app委托中写一段常用代码

Question

在我的项目中，我想隐藏主指示器，而不需要在每个视图控制器中写同样的代码，而是在appDelegate中实现它。我试过

   - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor yellowColor];
    return YES;
}

-(BOOL)prefersHomeIndicatorAutoHidden{
    return YES;
}

我试过这样做，但它不常见。那么，我怎样才能不在每个视图控制器中写代码，而在app delegate中实现隐藏原点指示器呢？

Answer 1

有一种方法可以实现这一点。在我看来，这不是最优雅的，我同意Gereon的说法，你最好创建一个子类 UIViewController在那里实现它，然后让你所有的视图控制器从这个基类继承。

然而，你可以使用Method Swizzling来实现。请看这里。https:/nshipster.commethod-swizzling。. 在你的情况下，你可以在AppDelegate中的Swizzle它。application: didFinishLaunchingWithOptions: 嗖嗖 prefersHomeIndicatorAutoHidden 到您的自定义函数，返回 YES.

所以对于swizzling我建议你新建一个UIViewController的Category。而实际的swizzling。

#import <objc/runtime.h>

@implementation UIViewController (Swizzling)

+ (void)load
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Class class = [self class];
        SEL originalSelector = @selector(prefersHomeIndicatorAutoHidden);
        SEL swizzledSelector = @selector(swizzledPrefersHomeIndicatorAutoHidden);
        Method originalMethod = class_getInstanceMethod(class, originalSelector);
        Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);

        const BOOL didAdd = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
        if (didAdd)
            class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
        else
            method_exchangeImplementations(originalMethod, swizzledMethod);
    });
}

- (BOOL)prefersHomeIndicatorAutoHidden
{
    return YES; //Doesn't matter what you return here. In this you could return the actual property value.
}

- (BOOL)swizzledPrefersHomeIndicatorAutoHidden //This is the actual `prefersHomeIndicatorAutoHidden ` call
{
    return YES;
}

@end