IOS [[UIApplication sharedapplication] delegate] "Apply

Before we get to the app window, we usually do this:

[UIApplication sharedApplication].keyWindow

This writing has always been felt right, no problem, and most of the online blog or material is also written, but recently in the project, found that this is not safe to write, if the application does not jump, this kind of writing is feasible, but if the application has a jump (share jump to other apps, Access to the System album, etc.), then return to the original app, you will find the loading of the original window on the location of the view will be significantly offset, read some information, found that if written

[[[UIApplication sharedApplication]delegate]window]

If you encounter this problem in your project, you may want to try this.

IOS [[UIApplication sharedapplication] delegate] "Apply