//设置20秒之后 

NSDate *date = [NSDate dateWithTimeIntervalSinceNow:];

    //chuagjian一个本地推送

    UILocalNotification *noti = [[[UILocalNotification alloc] init] autorelease];

    if (noti) {

        //设置推送时间

        noti.fireDate = date;

        //设置时区

        noti.timeZone = [NSTimeZone defaultTimeZone];

        //设置重复间隔

        noti.repeatInterval = NSWeekCalendarUnit;

        //推送声音

        noti.soundName = UILocalNotificationDefaultSoundName;

        //内容

        noti.alertBody = @"推送内容";

        //显示在icon上的红色圈中的数子

        noti.applicationIconBadgeNumber = ;

        //设置userinfo 方便在之后需要撤销的时候使用

        NSDictionary *infoDic = [NSDictionary dictionaryWithObject:@"name" forKey:@"key"];

        noti.userInfo = infoDic;

        //添加推送到uiapplication        

        UIApplication *app = [UIApplication sharedApplication];

        [app scheduleLocalNotification:noti];  

    }

- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification*)notification

{

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"接收到本地提醒 in app"

message:notification.alertBody

   delegate:nil

  cancelButtonTitle:@"确定"

  otherButtonTitles:nil];

[alert show];

//这里，你就可以通过notification的useinfo，干一些你想做的事情了

application.applicationIconBadgeNumber -= ;

}

UIApplication *app = [UIApplication sharedApplication];

    //获取本地推送数组

    NSArray *localArr = [app scheduledLocalNotifications];

    //声明本地通知对象

    UILocalNotification *localNoti;

    if (localArr) {

        for (UILocalNotification *noti in localArr) {

            NSDictionary *dict = noti.userInfo;

            if (dict) {

                NSString *inKey = [dict objectForKey:@"key"];

                if ([inKey isEqualToString:key]) {

                    if (localNoti){

                        [localNoti release];

                        localNoti = nil;

                    }

                    localNoti = [noti retain];

                    break;

                }

            }

        }

        //判断是否找到已经存在的相同key的推送

        if (!localNoti) {

            //不存在 初始化

            localNoti = [[UILocalNotification alloc] init];

        }

        if (localNoti && !state) {

            //不推送 取消推送

            [app cancelLocalNotification:localNoti];

            [localNoti release];

            return;

        }

}