Non-arc and ARC projects go with each other

If your project uses a non-arc mode, add the-FOBJC-ARC tag for the ARC mode code file.

If your project uses the ARC mode, add the-FNO-OBJC-ARC tag for code files that are not in arc mode.

How to add a label:

1. Open: Your target->bulid phases->compile Sources.

2. Double-click the corresponding *.m file.

3. Enter the label mentioned above in the pop-up window-fobjc-arc/-fno-objc-arc

4. Press the ENTER key directly to save

Add Compile Error

#if!__has_feature (OBJC_ARC)

#error This class requires automatic reference counting.

#endif