【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];

        

    }];

转载于:https://www.cnblogs.com/pjl0426/p/4931425.html