iOS 本地通知详解

//
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    _window=[[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];

    _window.backgroundColor =[UIColor colorWithRed:249/255.0 green:249/255.0 blue:249/255.0 alpha:1];

    //设置全局导航条风格和颜色
    [[UINavigationBar appearance] setBarTintColor:[UIColor colorWithRed:23/255.0 green:180/255.0 blue:237/255.0 alpha:1]];
    [[UINavigationBar appearance] setBarStyle:UIBarStyleBlack];

    KCMainViewController *mainController=[[KCMainViewController alloc]init];
    _window.rootViewController=mainController;

    [_window makeKeyAndVisible];
    //如果已经获得发送通知的授权则创建本地通知，否则请求授权(注意：如果不请求授权在设置中是没有对应的通知设置项的，也就是说如果从来没有发送过请求，即使通过设置也打不开消息允许设置)
    if  ([[UIApplication sharedApplication]currentUserNotificationSettings].types!=UIUserNotificationTypeNone) {
        [self addLocalNotification];
    } else {
        [[UIApplication sharedApplication]registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound  categories:nil]];
    }

    return  YES;
}
#pragma mark 调用过用户注册通知方法之后执行（也就是调用完registerUserNotificationSettings:方法之后执行）
-(void)application:(UIApplication *)application didRegisterUserNotificationSettings:(UIUserNotificationSettings *)notificationSettings{
    if  (notificationSettings.types!=UIUserNotificationTypeNone) {
        [self addLocalNotification];
    }
}
#pragma mark 进入前台后设置消息信息
-(void)applicationWillEnterForeground:(UIApplication *)application{
    [[UIApplication sharedApplication]setApplicationIconBadgeNumber:0]; //进入前台取消应用消息图标
}
#pragma mark - 私有方法
#pragma mark 添加本地通知
-(void)addLocalNotification{

    //定义本地通知对象
    UILocalNotification *notification=[[UILocalNotification alloc]init];
    //设置调用时间
    notification.fireDate=[NSDate dateWithTimeIntervalSinceNow:10.0]; //通知触发的时间，10s以后
    notification.repeatInterval=2; //通知重复次数
    //notification.repeatCalendar=[NSCalendar currentCalendar];//当前日历，使用前最好设置时区等信息以便能够自动同步时间

    //设置通知属性
    notification.alertBody=@ "最近添加了诸多有趣的特性，是否立即体验？" ;  //通知主体
    notification.applicationIconBadgeNumber=1; //应用程序图标右上角显示的消息数
    notification.alertAction=@ "打开应用" ;  //待机界面的滑动动作提示
    notification.alertLaunchImage=@ "Default" ; //通过点击通知打开应用时的启动图片,这里使用程序启动图片
    //notification.soundName=UILocalNotificationDefaultSoundName;//收到通知时播放的声音，默认消息声音
    notification.soundName=@ "msg.caf" ; //通知声音（需要真机才能听到声音）

    //设置用户信息
    notification.userInfo=@{@ "id" :@1,@ "user" :@ "Kenshin Cui" }; //绑定到通知上的其他附加信息

    //调用通知
    [[UIApplication sharedApplication] scheduleLocalNotification:notification];
}
#pragma mark 移除本地通知，在不需要此通知时记得移除
-(void)removeNotification{
    [[UIApplication sharedApplication] cancelAllLocalNotifications];
}
@end

首先是添加一个本地通知到系统中，代码如下：

// 初始化本地通知对象
UILocalNotification *notification = [[UILocalNotification alloc] init];
if (notification) {
    // 设置通知的提醒时间
    NSDate *currentDate   = [NSDate date];
    notification.timeZone = [NSTimeZone defaultTimeZone]; // 使用本地时区
    notification.fireDate = [currentDate dateByAddingTimeInterval: 5.0 ];

    // 设置重复间隔
    notification.repeatInterval = kCFCalendarUnitDay;

    // 设置提醒的文字内容
    notification.alertBody   = @ "Wake up, man" ;
    notification.alertAction = NSLocalizedString(@ "起床了" , nil);

    // 通知提示音 使用默认的
    notification.soundName= UILocalNotificationDefaultSoundName;

    // 设置应用程序右上角的提醒个数
    notification.applicationIconBadgeNumber++;

    // 设定通知的userInfo，用来标识该通知
    NSMutableDictionary *aUserInfo = [[NSMutableDictionary alloc] init];
    aUserInfo[kLocalNotificationID] = @ "LocalNotificationID" ;
    notification.userInfo = aUserInfo;

    // 将通知添加到系统中
    [[UIApplication sharedApplication] scheduleLocalNotification:notification];
}

上面的alertBody是设备收到本地通知时横额或锁屏时的主要文字内容，alertActions是锁屏时显示的slide to后面的文字内容。例如：

repeatInterval表示通知的重复间隔，在SDK中定义如下：

<喎�"http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHByZSBjbGFzcz0="brush:java;">@property(nonatomic) NSCalendarUnit repeatInterval; // 0 means don't repeat
其取值主要有：

NSCalendarUnitEra                = kCFCalendarUnitEra,
NSCalendarUnitYear               = kCFCalendarUnitYear,
NSCalendarUnitMonth              = kCFCalendarUnitMonth,
NSCalendarUnitDay                = kCFCalendarUnitDay,
NSCalendarUnitHour               = kCFCalendarUnitHour,
NSCalendarUnitMinute             = kCFCalendarUnitMinute,
NSCalendarUnitSecond             = kCFCalendarUnitSecond,
NSCalendarUnitWeekday            = kCFCalendarUnitWeekday,
NSCalendarUnitWeekdayOrdinal     = kCFCalendarUnitWeekdayOrdinal,

分别表示一个世纪、一年、一个月等等，0表示不重复。具体可以查看CFCalendar Reference

repeatInterval的下限应该是NSCalendarUnitMinute，即每分钟重复发送一次通知。

如果设置为NSCalendarUnitSecond，那么消息不会重复，每秒发送一次通知，iOS系统当然不会容许这样的存在了。

这里比较不好的一点是该值不能自定义（很遗憾，NSCalendarUnit是个枚举类型），例如你不能塞个10.0给它从而希望它每十秒重复一次。所以如果你想每20分钟发送一次通知，一小时内发送3次，那么只能同时设定三个通知了。

上面的代码运行后，5秒钟之后就可以收到一个本地通知。

在收到通知后，调用程序委托中的下列方法处理：

-( void )application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification{
    NSLog(@ "Application did receive local notifications" );

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@ "Hello" message:@ "welcome" delegate:nil cancelButtonTitle:@ "OK" otherButtonTitles:nil, nil];
    [alert show];
}

注意这个方法只有在程序启动之后才会执行，因此当程序处于后台时，该方法不会执行。

有一点需要注意，如果我们的应用程序给系统发送的本地通知是周期性的，那么即使把程序删了重装，之前的本地通知在重装时依然存在（没有从系统中移除）。例如，我们在viewDidLoad方法中启动添加本地通知的方法，多跑几次，然后把程序在模拟器中删除，再重新跑，并用下列方法输出所有的本地通知：

NSArray *localNotifications = [[UIApplication sharedApplication] scheduledLocalNotifications];
NSLog(@ "%@" , localNotifications);

控制台输出：

2014 - 03 - 14 15 : 46 : 37.145 LocalNotificationDemo[ 4419 :60b] (
    "<uiconcretelocalnotification: 0xa32ce30=" ">{fire date = Friday, March 14, 2014 at 3:38:16 PM China Standard Time, time zone = Asia/Chongqing (GMT+8) offset 28800, repeat interval = NSDayCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, March 15, 2014 at 3:38:16 PM China Standard Time, user info = {\n    ClockID = LocalNotificationID;\n}}" ,
    "<uiconcretelocalnotification: 0xa32dfc0=" ">{fire date = Friday, March 14, 2014 at 3:44:45 PM China Standard Time, time zone = Asia/Chongqing (GMT+8) offset 28800, repeat interval = NSDayCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, March 15, 2014 at 3:44:45 PM China Standard Time, user info = {\n    ClockID = LocalNotificationID;\n}}" ,
    "<uiconcretelocalnotification: 0xa32e470=" ">{fire date = Friday, March 14, 2014 at 3:44:55 PM China Standard Time, time zone = Asia/Chongqing (GMT+8) offset 28800, repeat interval = NSDayCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, March 15, 2014 at 3:44:55 PM China Standard Time, user info = {\n    ClockID = LocalNotificationID;\n}}" ,
    "<uiconcretelocalnotification: 0xa32e950=" ">{fire date = Friday, March 14, 2014 at 3:45:13 PM China Standard Time, time zone = Asia/Chongqing (GMT+8) offset 28800, repeat interval = NSDayCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, March 15, 2014 at 3:45:13 PM China Standard Time, user info = {\n    ClockID = LocalNotificationID;\n}}" ,
    "<uiconcretelocalnotification: 0xa32edb0=" ">{fire date = Friday, March 14, 2014 at 3:45:29 PM China Standard Time, time zone = Asia/Chongqing (GMT+8) offset 28800, repeat interval = NSDayCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, March 15, 2014 at 3:45:29 PM China Standard Time, user info = {\n    ClockID = LocalNotificationID;\n}}" ,
    "<uiconcretelocalnotification: 0xa32e870=" ">{fire date = Friday, March 14, 2014 at 3:46:28 PM China Standard Time, time zone = Asia/Chongqing (GMT+8) offset 28800, repeat interval = NSDayCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, March 15, 2014 at 3:46:28 PM China Standard Time, user info = {\n    ClockID = LocalNotificationID;\n}}"
)</uiconcretelocalnotification:></uiconcretelocalnotification:></uiconcretelocalnotification:></uiconcretelocalnotification:></uiconcretelocalnotification:></uiconcretelocalnotification:>

可以看到之前发送的本地通知一直滞留在系统中。

不只是模拟器，在iOS设备上也是这样，博主之前的App在设备上重装时以前的本地通知会继续发送。

因此我们需要取消通知的方法，当然该对象也会在scheduledLocalNotifications数组中移除。

取消方法分为两种。

第一种比较暴力，直接取消所有的本地通知：

[[UIApplication sharedApplication] cancelAllLocalNotifications];

这个适合在App重装时第一次启动的时候，或还原程序默认设置等场合下使用。

第二种方法是针对某个特定通知的：

- ( void )cancelLocalNotification:(UILocalNotification *)notification NS_AVAILABLE_IOS(4_0);

这时就需要通知有一个标识，这样我们才能定位是哪一个通知。可以在notification的userInfo（一个字典）中指定。

例如：

-( void )application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification{
    NSLog(@ "Application did receive local notifications" );

    // 取消某个特定的本地通知
    for (UILocalNotification *noti in [[UIApplication sharedApplication] scheduledLocalNotifications]) {
        NSString *notiID = noti.userInfo[kLocalNotificationID];
        NSString *receiveNotiID = notification.userInfo[kLocalNotificationID];
        if ([notiID isEqualToString:receiveNotiID]) {
            [[UIApplication sharedApplication] cancelLocalNotification:notification];
            return ;
        }
    }

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@ "Hello" message:@ "welcome" delegate:nil cancelButtonTitle:@ "OK" otherButtonTitles:nil, nil];
    [alert show];
}

最后建议本地通知不要发得太频繁，不然用户会觉得非常的烦。