App keeps crashing when switching screens via button

[eojin9642]

Hello all!
I'm developing a simple app which displays information based on the category you choose.
To achieve that, I used TinyDB to store data of which button was pressed, which would then show a different result on another screen.

Currently I'm just working on the bare-bones framework of the system, so I can add more details later, but at a point, it was refusing to let me set the background color of the screens to white. Any other color was fine, but setting it to white (through any method) lead to the color being switched back to "Default" immediately. So, I used "When screen is initialized, set screen background color to..." to set the color to white.

But after I did that, it started constantly crashing whenever I pressed a button to switch screens. At first it would crash when I rapidly switched between screens, but now it crashes when I first start the app and press a button to switch from screen 2 to 3. (The entire app turns off)

It's been a while since I coded anything, and this is my first project in a while. Am I making a glaring mistake that I'm just not aware of?

I've included the file below, please tell me if anything else is needed!

Thank you.

buttontest.aia (42.2 KB)

[TIMAI2]

1. You neglected to mention that you were using clock timers. Clocks need to be stopped before switching screens. This is probably the cause of your crashes
2. You should learn how to switch screens correctly, your current approach leaves screens open, which will build the stack and eventually cause an Out Of Memory message

[eojin9642]

Thank you very much! I suspected it might've involved the clocks.
I put in "When clock Timer -> Set Clock timer enabled to False" - that should fix it.

As for your second point, do you have any resources you can point to, in order to help me figure out how to turn off the screen when switching to another?

Thank you again

[TIMAI2]

How to use Virtual Screens

Hey, everyone! Hope you all are having a great day so far! Today I would like to introduce you to the topic of using virtual screens as not many people know how to use virtual screens. To start off, I would like to tell you all that using virtual screens is much better than using regular screens, especially if you think you will be using more than ten screens as MIT App Inventor can not accommodate more than ten screens. In fact in @Peter ‘s post about General Tips and Tricks for App Inventor wi…

also

Use different screens wisely

• Before starting to create another screen, first you should think about is it really necessary? 
• See also Building apps with many screens and SteveJG's post about advantages/disadvantages, because in only one screen you also can use vertical arrangements to simulate different screens, just set the arrangements to visible = true/false as needed... 
• See also Martyn_HK's example about how to use Tabs in App Inventor and another example from Cyd. and my Tabbed Screens Demo

If you decided to use different screens, then you should switch them correctly, else you will run out of memory after a while...      
The recommended method of switching screens in App Inventor

(Thanks Taifun)

 

Also see demo: multiscreen.aia

 

[eojin9642]

Thank you, this should work well

[Anke]

@TIMAI2

Clocks need to be stopped before switching screens.

Yes, but only if the screen is not closed with / after screen switching.
However, if the screen is closed, the clock / timer is automatically disabled.