UIApplication详解

每个app有且只有一个UIApplication对象，当程序启动的时候通过调用UIApplicationMain方法得到的。可以通过sharedApplication方法得到。

UIApplication对象的主要任务是处理用户事件的处理路径，例如分发一个UIEvent到另外一个对象去处理。UIApplication对象持有众多的UIWindow对象，因此可以组织app的展示。UIApplication对象还能处理一些资源，例如通过openURL:打开邮箱客户端或者设置界面等。

获得UIApplication对象

[UIApplication sharedApplication]

获得UIApplicationDelegate对象

[[UIApplication sharedApplication] delegate]

获得UIWindow对象

[[UIApplication sharedApplication] windows];   //UIWindow数组[[UIApplication sharedApplication] keyWindow]; //UIWindow数组中最后调用makeKeyAndVisible方法的UIWindow对象

控制和处理UIEvent

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{//分发一个event到另外一个对象去处理    [[UIApplication sharedApplication] sendAction:@selector(action: forEvent:) to:[CustomHandler sharedCustomHandler] from:self forEvent:event];}

[[UIApplication sharedApplication] beginIgnoringInteractionEvents]; //开始忽略Event//...中间调用动画等操作[[UIApplication sharedApplication] endIgnoringInteractionEvents];   //结束忽略Event

[UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;  //晃动是否有撤销或者重做动作

打开URL资源

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];//打开设置界面

配置通知设置

UIUserNotificationType  types = UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert;UIUserNotificationSettings  *mySettings  = [UIUserNotificationSettings settingsForTypes:types categories:nil];[[UIApplication sharedApplication] registerUserNotificationSettings:mySettings]; //注册远程推送通知

[[UIApplication sharedApplication] registerForRemoteNotifications];//注册[[UIApplication sharedApplication] unregisterForRemoteNotifications];//注销

    NSDate *date = [NSDate dateWithTimeIntervalSinceNow:10];    UILocalNotification *localNotif = [[UILocalNotification alloc] init];    localNotif.fireDate = date;  //时间    localNotif.timeZone = [NSTimeZone localTimeZone]; //时区    localNotif.repeatInterval = NSCalendarUnitMinute; //间隔    localNotif.soundName = UILocalNotificationDefaultSoundName; //声音    localNotif.alertBody = @"Local Test";   //通知内容    localNotif.applicationIconBadgeNumber = 1;  //数字标示    localNotif.userInfo = @{@"key":@"test"};    //info    [[UIApplication sharedApplication] scheduleLocalNotification:localNotif]; //注册通知

    [[UIApplication sharedApplication] presentLocalNotificationNow:localNotif]; //立即通知    [[UIApplication sharedApplication] cancelAllLocalNotifications]; //取消所有通知    [[UIApplication sharedApplication] cancelLocalNotification:localNotif]; //取消特定的通知        NSArray *arr = [[UIApplication sharedApplication] scheduledLocalNotifications];  //所有的通知

后台运行相关

    [[UIApplication sharedApplication] applicationState]; //app状态      [[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:3600]; //设置后台运行时间    NSTimeInterval remainTime = [[UIApplication sharedApplication] backgroundTimeRemaining]; //app后台运行的时间    NSLog(@"remainTIme = %f",remainTime);    int state = [[UIApplication sharedApplication] backgroundRefreshStatus]; //后台刷新的状态    NSLog(@"state = %d",state);    [[UIApplication sharedApplication] beginBackgroundTaskWithName:@"taskOne" expirationHandler:^{    }];    [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{     }];    [[UIApplication sharedApplication] endBackgroundTask:1];

远程的控制相关

    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];    [[UIApplication sharedApplication] endReceivingRemoteControlEvents];

系统的Idle Timer

[UIApplication sharedApplication].idleTimerDisabled = YES; //不让手机休眠

APP样式

    //隐藏状态条    [[UIApplication sharedApplication] setStatusBarHidden:YES];    [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationSlide];    //设置状态条的样式    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];    [[UIApplication sharedApplication] statusBarStyle];    //状态条的Frame    [[UIApplication sharedApplication] statusBarFrame];    //网络是否可见    [[UIApplication sharedApplication] isNetworkActivityIndicatorVisible];    //badge数字    [UIApplication sharedApplication].applicationIconBadgeNumber = 2;    //屏幕的方向    [[UIApplication sharedApplication] userInterfaceLayoutDirection];

设置状态条的方向

[[UIApplication sharedApplication] setStatusBarOrientation:UIInterfaceOrientationLandscapeLeft animated:YES];

数据类型

UIBackgroundTaskIdentifier : Int

typedef enum : NSUInteger {   UIRemoteNotificationTypeNone    = 0,   UIRemoteNotificationTypeBadge   = 1 << 0,   UIRemoteNotificationTypeSound   = 1 << 1,   UIRemoteNotificationTypeAlert   = 1 << 2,   UIRemoteNotificationTypeNewsstandContentAvailability = 1 << 3} UIRemoteNotificationType;

typedef enum : NSInteger {   UIStatusBarStyleDefault,   UIStatusBarStyleLightContent,      UIStatusBarStyleBlackTranslucent,   UIStatusBarStyleBlackOpaque} UIStatusBarStyle;

typedef enum : NSInteger {   UIStatusBarAnimationNone,   UIStatusBarAnimationFade,   UIStatusBarAnimationSlide,} UIStatusBarAnimation;

typedef enum : NSInteger  {   UIApplicationStateActive ,   UIApplicationStateInactive ,   UIApplicationStateBackground } UIApplicationState;

const UIBackgroundTaskIdentifier  UIBackgroundTaskInvalid ;const NSTimeInterval  UIMinimumKeepAliveTimeout;

typedef enum : NSUInteger  {   UIBackgroundFetchResultNewData ,   UIBackgroundFetchResultNoData ,   UIBackgroundFetchResultFailed } UIBackgroundFetchResult;

const NSTimeInterval  UIApplicationBackgroundFetchIntervalMinimum ;const NSTimeInterval  UIApplicationBackgroundFetchIntervalNever;

typedef enum : NSUInteger  {   UIBackgroundRefreshStatusRestricted ,   UIBackgroundRefreshStatusDenied ,   UIBackgroundRefreshStatusAvailable } UIBackgroundRefreshStatus;

typedef enum : NSInteger  {   UIInterfaceOrientationUnknown             = UIDeviceOrientationUnknown ,   UIInterfaceOrientationPortrait            = UIDeviceOrientationPortrait ,   UIInterfaceOrientationPortraitUpsideDown  = UIDeviceOrientationPortraitUpsideDown ,   UIInterfaceOrientationLandscapeLeft       = UIDeviceOrientationLandscapeRight ,   UIInterfaceOrientationLandscapeRight      = UIDeviceOrientationLandscapeLeft } UIInterfaceOrientation;

typedef enum : NSInteger  {   UIUserInterfaceLayoutDirectionLeftToRight ,   UIUserInterfaceLayoutDirectionRightToLeft ,} UIUserInterfaceLayoutDirection;

NSString *const  UIApplicationOpenSettingsURLString;

NSString *const  UIApplicationStatusBarOrientationUserInfoKey ;NSString *const  UIApplicationStatusBarFrameUserInfoKey;

NSString *const  UIContentSizeCategoryExtraSmall ;NSString *const  UIContentSizeCategorySmall ;NSString *const  UIContentSizeCategoryMedium ;NSString *const  UIContentSizeCategoryLarge ;NSString *const  UIContentSizeCategoryExtraLarge ;NSString *const  UIContentSizeCategoryExtraExtraLarge ;NSString *const  UIContentSizeCategoryExtraExtraExtraLarge;

NSString *const  UIContentSizeCategoryAccessibilityMedium ;NSString *const  UIContentSizeCategoryAccessibilityLarge ;NSString *const  UIContentSizeCategoryAccessibilityExtraLarge ;NSString *const  UIContentSizeCategoryAccessibilityExtraExtraLarge ;NSString *const  UIContentSizeCategoryAccessibilityExtraExtraExtraLarge;

NSString *const  UIApplicationInvalidInterfaceOrientationException;

通知

UIApplicationBackgroundRefreshStatusDidChangeNotificationUIApplicationDidBecomeActiveNotificationUIApplicationDidChangeStatusBarFrameNotificationUIApplicationDidChangeStatusBarOrientationNotificationUIApplicationDidEnterBackgroundNotificationUIApplicationDidFinishLaunchingNotificationUIApplicationDidReceiveMemoryWarningNotificationUIApplicationProtectedDataDidBecomeAvailableUIApplicationProtectedDataWillBecomeUnavailableUIApplicationSignificantTimeChangeNotificationUIApplicationUserDidTakeScreenshotNotificationUIApplicationWillChangeStatusBarOrientationNotificationUIApplicationWillChangeStatusBarFrameNotificationUIApplicationWillEnterForegroundNotificationUIApplicationWillResignActiveNotificationUIApplicationWillTerminateNotificationUIContentSizeCategoryDidChangeNotification