APP: Close background when main window is closed
APP: Close background when main window is closed

Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano