Terminating app due to uncaught exception for iOS development ", reason, ** first throw call Stack: Error Handling

When I encountered this problem during my project today, I shared that this should be only one of the reasons for this error. But also want to record down for your reference, if you also encounter such a problem, at the same time is caused by other reasons, please send Email: sanpintian@gmail.com

Complete error code:

The cause of the error is:

The above four input boxes are all UITextView. When you click Login, if either of the four input boxes is empty, an error is returned.

This requires us to design our program robustness, set UITextView or remind users.

I hope it will be helpful to you.