Hello,
Can anyone help me?
I'm trying to create a personal agenda using the listview. What happens is: the listview becomes invisible on screen 2 and where the person adds the task to save it, but when they go to screen 3 the listview is invisible.
Why this if then lovic? Before this logic tko you are adding the value inti listview... Do you any value inthe tinydb?
Screen 2 is not storing a list in TinyDB.
no? where is the error
A text Join doesn't create a list.
It creates a piece of text.
Look in button 1
I hadn't seen it, can you tell me which block I should put in its place?
Keep the join, but feed it into an Add Item to List block.
You have to clear TinyDB.
If you want to store each event as an item in a list and the list in TinyDB then learn how to work with lists
A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook App Inventor 2 Book: Create Your Own Android Apps ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.
There is a free programming course here Course In A Box and the aia files for the projects in the book are here: App Inventor 2 Book: Create Your Own Android Apps
How to do a lot of basic things with App Inventor are described here: How do you...? .
Also do the tutorials Our Tutorials! to learn the basics of App Inventor, then try something and follow the Top 5 Tips: How to learn App Inventor
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.
On a different note Samuel (sorry to bombard you with information and questions), you would probably find it much easier to manage your App if you used Virtual Screens. However, Virtual or not, you really should ask yourself if three screens are necessary. The best Apps from a User perspective are kept as simple as possible and the code that drives them "lean and mean".