3: QT -- how to set debug code

After write a small test project, the project can run successfully, but breakpoint does not take effect.

So set to Debug mode:

　　Add this to XXX.pro　　CONFIG+=debug

So set to Release mode:

 　　Add this to XXX.pro　　CONFIG+=release

 

After change the mode, must clean the project and rebuild again, the new mode will take affect.