iOS creates Category category (extension class)

I want to extend UIButton with methods other than those provided by other systems, so I need to use an extension class.

The creation steps are as follows:

Step 1: New File

Step 2: Select Objective-c File

Step 3: Name the File casually (AaaBtn is written here), and inherit the Class to UIButton

Step 4: The created UIButton extension class is as follows

After creation, you can write the Button's extended attributes in the file.