【iOS学习笔记】IOS开发中设置applicationIconBadgeNumber和消息推送

因为在IOS8中要想设置applicationIconBadgeNumber，需要用户的授权，在IOS8中，需要加上下面的代码：

UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];

[[UIApplication sharedApplication] registerUserNotificationSettings:settings];

 

但是这两句如果是在IOS7的系统中运行的话就会报错，所以需要先判断IOS的版本，完整代码如下： 

float version = [[[UIDevice currentDevice] systemVersion] floatValue];

     

if (version >= 8.0) {

    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];

    [[UIApplication sharedApplication] registerUserNotificationSettings:settings];

}

如果是注册消息推送的话，需要这样写： 

 

float version = [[[UIDevice currentDevice] systemVersion] floatValue];

 

if (version >= 8.0) {

    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];

    [[UIApplication sharedApplication] registerUserNotificationSettings:settings];

    [application registerForRemoteNotifications];

}

 

向操作系统申请后台运行的资格，能维持多久，是不确定的

 UIBackgroundTaskIdentifier task = [application beginBackgroundTaskWithExpirationHandler:^{

       当申请的后台运行时间已经结束（过期），就会调用这个block

        

        赶紧结束任务

        [application endBackgroundTask:task];

        

    }];