区分iOS7上的屏幕锁定和主页按钮按下

Question

我需要在applicationDidEnterBackground 做点什么。但我需要区分导致“进入背景”的用户操作：屏幕锁定或主页按钮按下。

我使用的是这段代码，来自post - How to differentiate between screen lock and home button press on iOS5?:

UIApplicationState state = [application applicationState];
if (state == UIApplicationStateInactive) {
    NSLog(@"Sent to background by locking screen");
} else if (state == UIApplicationStateBackground) {
    NSLog(@"Sent to background by home button/switching to other app");
}

它在 iOS6 上运行良好。但在 iOS7（设备和模拟器）上，无论用户点击主页还是锁定按钮，我总是得到UIApplicationStateBackground。

有人知道可能导致这种情况的原因吗？ iOS 7 更新多任务后台处理？或者我的应用程序的某些设置（我的应用程序的后台模式已关闭）？

还有其他解决方案吗？

Answer 1

这对 iOS6 和 iOS7 都有帮助:)。

当用户按下锁定按钮时，您将收到com.apple.springboard.lockcomplete 通知。

//new way
//put this in - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(),
                                    NULL,
                                    displayStatusChanged,
                                    CFSTR("com.apple.springboard.lockcomplete"),
                                    NULL,
                                    CFNotificationSuspensionBehaviorDeliverImmediately);

//put this function in AppDelegate
static void displayStatusChanged(CFNotificationCenterRef center,
                                 void *observer,
                                 CFStringRef name,
                                 const void *object,
                                 CFDictionaryRef userInfo) {
    if (name == CFSTR("com.apple.springboard.lockcomplete")) {
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"kDisplayStatusLocked"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
}

//put this in onAppEnterBackground
UIApplicationState state = [[UIApplication sharedApplication] applicationState];
    if (state == UIApplicationStateInactive) {
        NSLog(@"Sent to background by locking screen");
    } else if (state == UIApplicationStateBackground) {
        if (![[NSUserDefaults standardUserDefaults] boolForKey:@"kDisplayStatusLocked"]) {
            NSLog(@"Sent to background by home button/switching to other app");
        } else {
            NSLog(@"Sent to background by locking screen");
        }
    }

//put this in - (void)applicationWillEnterForeground:(UIApplication *)application
[[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"kDisplayStatusLocked"];
[[NSUserDefaults standardUserDefaults] synchronize];

CGFloat screenBrightness = [[UIScreen mainScreen] brightness];

NSLog(@"Screen brightness: %f", screenBrightness);

UIApplicationState state = [[UIApplication sharedApplication] applicationState];

if (state == UIApplicationStateInactive) {

    NSLog(@"Sent to background by locking screen");

} else if (state == UIApplicationStateBackground) {
    if (screenBrightness > 0.0) {
        NSLog(@"Sent to background by home button/switching to other app");
    } else {
        NSLog(@"Sent to background by locking screen");
    }
}

Answer 2

它在 Swift 中不起作用，您需要进行一些修改以使其在 Swift 中起作用，如下所示

1.创建一个名为LockNotifierCallback.m的objectiveC文件，如下：

static void displayStatusChanged(CFNotificationCenterRef center,
                                 void *observer,
                                 CFStringRef name,
                                 const void *object,
                                 CFDictionaryRef userInfo) {
    if ([(__bridge NSString *)name  isEqual: @"com.apple.springboard.lockcomplete"]) {
        NSLog(@"Screen Locked");
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"kDisplayStatusLocked"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
}

@implementation LockNotifierCallback

+ (void(*)(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo))notifierProc {
return displayStatusChanged;
}

@end

同时创建一个头部： #导入

@interface LockNotifierCallback : NSObject


+ (void(*)(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo))notifierProc;


@end

2.将此文件桥接到swift

3.在APPdelegate.swift中添加函数：

CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), nil, LockNotifierCallback.notifierProc(), "com.apple.springboard.lockcomplete", nil, CFNotificationSuspensionBehavior.DeliverImmediately)

PS:UIApplicationState 在这里不能完美运行

Answer 3

此解决方案取自 this answer 并为我工作。它有点 hacky，但它更容易被应用商店接受，因为它不使用 com.apple.springboard.lockcomplete 或 com.apple.springboard.lockstate.

以下代码进入您的 AppDelegate：

func applicationDidEnterBackground(_ application: UIApplication) {
    if (DidUserPressLockButton()) {
        print("User pressed lock button")
    } else {
        print("user pressed home button")
    }
}

private func DidUserPressLockButton() -> Bool {
    let oldBrightness = UIScreen.main.brightness
    UIScreen.main.brightness = oldBrightness + (oldBrightness <= 0.01 ? (0.01) : (-0.01))
    return oldBrightness != UIScreen.main.brightness
}

想法是在应用程序进入后台后尝试更改屏幕亮度并检查此更改是否成功。

免责声明：它在模拟器上不起作用，您必须在真实设备上进行测试。