IOS Common faces trying to summarize 2

1. Please describe the differences between storyboard and xib?

In a project. can have multiple xib files, a xib file corresponding to a view class controller, and multiple views.

However. Use

When storyboard, a project needs only a master storyboard file to be able to. Therefore, in cases involving multiple attempts to control the

Storyboard management is more convenient, and storyboard can also describe the navigation between the narrative interface

Relationship.

2. Please list the singleton classes in the iOS system?

UIApplication (Application instance)

Nsuserdefault (Application settings)

Nsfilemanager (file Management)

Nsurlcache (Request cache)

Nsnotificationcenter (Message Center)

Nshttpcookiestorage (Application Cookies Pool)

3. Please outline your understanding of the synchronous/asynchronous request data?

1. The synchronization request is able to request data from the network, and once the synchronization request is sent, the program stops interacting with the user until the server returns data

Yes. Ability to do the next steps.

2. Asynchronous requests do not block the main thread. Instead, a new thread is created to operate. After the user makes an asynchronous request. The UI can still be

Operation, the program can continue execution.

IOS Common faces trying to summarize 2