after the side bar close and before in about 1s , the “when Screen1 back pressed” not work.
in normal circumstances, when i click the back button , it will stay in screen “main” , but if i close the side bar and quick click the back button,it wll go to the before screen
Call some event when screen back press which you want adfter back press
If I don’t call a event when screen back press , it just stay in the now screen all the time
Exactly. So you have to call some event like close application or notice to close application or open another screen.
You cant keep it blank, if so then nothing will happen by back press.
Hope it will help you.
ok, thank you 
.But my problem is, after the side bar close and in 1s before,the event will not work.
like this , it will not open the Screen2 if i click back button when i close the side bar
Yes. Thats right.
When you open side bar and bach press then side bar will close and then when you again back press then screen2 will open.
This will happen simultaneously not at same time.
If oou want to open screen 2 from side bar then you can add a button in side bar menu which when clicked screen 2 will open.
I know now, thank you:微笑: