iOS Edge Learning--segue data inversion (block instead of delegate)

The similarities and differences between block and method:

• The same point is to save the code snippet, when to execute, when to call
• The difference is that the block is not constrained by the class or object, and the method receives a constraint on the class or object

Second, the idea: (Contacts practice)

In the contact controller, you need to refresh the contact controller when you have finished adding contacts or when you have finished modifying the contacts TableView

However, the contact controller cannot determine when to refresh the TableView

Workaround: Define the block code snippet for the controller in the contact controller, and the block execution time is specified by the owner of the block

Third, the code implementation:

iOS Edge Learning--segue data inversion (block instead of delegate)