知道如果應用程序在WillResignActive中移動到背景？

Question

是否有知道WillResignActive是由於將應用程序移至背景還是由於打開控制/消息中心？

Answer 1

如果您的應用已移至後臺，則還會發送DidEnterBackground消息。您可以在WillResignActive之後的一小段延遲後檢查是否發送了兩封郵件。

編輯：選中該代碼

@interface HSAppDelegate() 
{ 
    BOOL _enteredBackground; 
} 

@end 

@implementation HSAppDelegate 

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
    NSLog(@"%s", __PRETTY_FUNCTION__); 
    _enteredBackground = NO; 
    _window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds]; 
    _window.rootViewController = [HSViewController new]; 
    [_window makeKeyAndVisible]; 

    return YES; 
} 

- (void)applicationWillResignActive:(UIApplication *)application 
{ 
    NSLog(@"%s", __PRETTY_FUNCTION__); 
    dispatch_async(dispatch_get_main_queue(), ^{ 
     if (!_enteredBackground) 
     { 
      // Do whatever you want here. 
     } 
     else 
     { 
      // This won't get called until the app comes back to foreground. 
     } 
    }); 
} 

- (void)applicationDidEnterBackground:(UIApplication *)application 
{ 
    NSLog(@"%s", __PRETTY_FUNCTION__); 
    _enteredBackground = YES; 
} 

- (void)applicationWillEnterForeground:(UIApplication *)application 
{ 
    NSLog(@"%s", __PRETTY_FUNCTION__); 
    _enteredBackground = NO; 
} 

- (void)applicationDidBecomeActive:(UIApplication *)application 
{ 
    NSLog(@"%s", __PRETTY_FUNCTION__); 
} 

@end