Determining Whether Multitasking Is Available
【Determining Whether Multitasking Is Available】
Apps must be prepared to handle situations where multitasking (and therefore background execution) is not available. Even if the device is running iOS 4 or later, the device may not support multitasking.
Apps必须处理无法后台运行的情况。即使设备在运行iOS4或以上版本,这台设备也可能不支持多任务 。
And multitasking is never available on devices running iOS 3 and earlier. If your app is capable of running on these earlier versions of iOS, it must be prepared to run without multitasking.
App后台运行无法跑在iOS3和早期版本里。如果你的app想要跑在低版本iOS上,必须处理好无法后台运行的情况。
If the presence or absence of multitasking changes the way your app behaves, check the multitaskingSupported property of the UIDevice class to determine whether multitasking is available before performing the relevant task.
在执行后台任务前,通过UIDevice的multitaskingSupported属性来判断是否支持多任务。
To do this, you must build your app against iOS SDK 4 or later and check to see if the property is available before accessing it, as shown in Listing 3-2. Checking the property allows your app to continue running on earlier versions of iOS that do not support multitasking.
Determining Whether Multitasking Is Available的更多相关文章
- Multi-tasking RTOS for microprocessors with limited memory by saving only a single return address per task during context switching
A real-time operating system (RTOS) for use with minimal-memory controllers has a kernel for managin ...
- [转载]协程-cooperative multitasking
[转载]协程三讲 http://ravenw.com/blog/2011/08/24/coroutine-part-1-defination-and-classification-of-corouti ...
- Determining Current Block and Current Item in Oracle Forms
SYSTEM.CURSOR_BLOCK Determining current block in Oracle Forms Using SYSTEM.CURSOR_BLOCK system varia ...
- Determining if a point lies on the interior of a polygon
Determining if a point lies on the interior of a polygon Written by Paul Bourke November 1987 Solut ...
- Determining IP information for eth0... failed; no link present. Check cable?
在RedHat下重启网络,service network restart之后,出现问题 Determining IP information for eth0... failed; no link p ...
- Determining Equality of Objects
[Determining Equality of Objects] If you need to determine whether one object is the same as another ...
- CANBus Determining Network Baud Rate, Automatic bit-rate detection
http://www.canbushack.com/blog/index.php?title=determining-network-baud-rate Determining Network Bau ...
- Determining IP information for eth0… failed; no link present. Check cable
[root@hexuweb101 ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0添加下面代码: check_link_down () { return ...
- 解决:Determining IP Information for eth0 一直停留 无法进入系统
问题场景: vm centos6.4网卡之前一直没异常,可今天启动时一直卡在Determining IP Information for eth0,无法进入系统.网上说了非常多办法,大多都是不着边的说 ...
随机推荐
- Spring bean作用域
全当知识要点记录了,大家随意踩踩. spring的作用域有以下几种singleton作用域prototype作用域request作用域session作用域global-session作用域 1. si ...
- 转-oracle中比较两表表结构差异和数据差异的方法
oracle中比较两表表结构差异和数据差异的方法 原作者:li2008xue2008ling 出处:http://blog.csdn.net 在工作中需要完成这么一个需求:比较两个表的表 ...
- [转]JavaScript RegExp 对象参考手册
JavaScript RegExp 对象参考手册 RegExp 对象 RegExp 对象表示正则表达式,它是对字符串执行模式匹配的强大工具. 直接量语法 /pattern/attributes 创建 ...
- sql在外键存在的情况下删除表
SQL Server 批量 停用/启用 外键约束 今天百度知道上面,看到这样一个要求: 现在有一个库,有很多张表想要删除一张表的记录的时候,由于外键关联太多,所以,没法删除相应的记录,谁能帮忙写个存储 ...
- javascript中 关于eval的那些事
javascript中的eval是一个非常灵活,但是灵活是伴随着风险的. 一.下面我们来看看那使用eval声明变量的问题. function test(x){ eval("var a=x;& ...
- Unity容器声明周期管理
Having said that, here is a solution that you can use with the Unity container: Create some custom a ...
- Oracle RAC 集群环境下日志文件结构
Oracle RAC 集群环境下日志文件结构 在Oracle RAC环境中,对集群中的日志的定期检查是必不可少的.通过查看集群日志,可以早期定位集群环境中出现的问题,以便将问题消灭在萌芽状态.简单介绍 ...
- 新建网站与新建Asp.Net Web 应用程序的区别
.net网站和应用程序区别,网站是动态执行的不用编译,他只依赖于自己的文档本身,甚至你用aspx里直接写jsp代码都可以,其实网站可以说只是在.net平台中打开的文档,相当于最初的记事本编码,他并不需 ...
- 关于json_encode转义斜杠的问题
加上参数 JSON_UNESCAPED_SLASHES即可 echo json_encode($data,JSON_UNESCAPED_SLASHES);
- Pthreads n 体问题
▶ <并行程序设计导论>第六章中讨论了 n 体问题,分别使用了 MPI,Pthreads,OpenMP 来进行实现,这里是 Pthreads 的代码,分为基本算法和简化算法(引力计算量为基 ...