ios – 如何检测设备上的iCloud帐户是否更改？

如何检测设备上使用的iCloud帐号是否已更改？

用户从“设置”> iCloud和另一个用户登录他/她的帐户.

打开应用程序时如何检测到此更改？

解决方法

只需添加名为NSUbiquityIdentityDidChangeNotification的通知的观察员

[[NSNotificationCenter defaultCenter]
    addobserver: self
       selector: @selector (iCloudAccountAvailabilityChanged:)
           name: NSUbiquityIdentityDidChangeNotification
         object: nil];

If a user signs out of iCloud,such as by turning off Documents & Data
in Settings,the ubiquityIdentityToken method returns nil. To enable
your app to detect when a user signs out and signs back in,register
for changes in iCloud account availability. – Apple Documentation

http://developer.apple.com/library/mac/#documentation/General/Conceptual/iCloudDesignGuide/Chapters/iCloudFundametals.html