What is not working for you ?
Also search this board for FAQ Lists
You can use TinyDb as you are - Save to TinyDb from one Screen, Read from TinyDb in the other Screen.
Easier if:
-
Virtual Screens are used.
When we define virtual screens, we use one 'real' App Inventor Screen (most often Screen1). Screen-sized Vertical Arrangements on it are displayed/hidden as required - they are the Virtual Screens. This is generally a better approach for multi-screen Apps, they share data without having to "pass" it between screens and it also reduces code duplication, making the App more efficient and the code easier to follow if you have to return to it at a later date.
So, instead of separate "houses", virtual screens are "rooms" of the same "house". -
Item data saved as a list under 1 TinyDb Tag:
For example, cart_item, cart_quantity, cart_price would be stored as:
Apple,6,£2.03
A TinyDb example in Blocks - very crude, much depends on how many items you have to process:
TinyDbList.aia (3.6 KB)
tinyDB