Problema ingresar nuevos campos en listview

[Christian_Araujo]

Hola solicito su amable ayuda, tengo un listview que muestra los registros ingresados, el problema es que cuando regreso desde el screen 2 al screen 1 y querer agregar otro registro a la lista existente en lugar de aumentar el registro en la lista se pierde los anteriores y sustituye por el actual ingresado.

Adjunto imagen del evento agregar datos:

En este screen inicialmente ingreso las asignaturas:

Y luego de regresar del screen 2 al 1 y querer ingresar otra asignatura a las 4 existentes se sustituye por el nuevo registro así como muestro a continuación:

Por favor su colaboración para superar este problema que ya he consultado y no puedo resolver, muchas gracias de antemano.

[TIMAI2]

You should show and identify your blocks for Screen1 and for Screen2, and your app screenshots as well (which Screen?).

[ABG]

FAQ Section: Books, Tips, Tutorials for AI2

Free Book Chapter 19 - Programming Lists of Data from http://www.appinventor.org/bookChapters/chapter19.pdf for translation Figure 19-1. [image] (picture of hands holding paper with printed list) CHAPTER 19 Programming Lists of Data As you’ve already seen, apps handle events and make decisions; such processing is fundamental to computing. But, the other fundamental part of an app is its data—the information it processes. An app’s data is rarely restricted to single memory slots such as…

You must learn to work with tables (lists of lists)

Don't store columns.

Store rows.

Also study dictionaries, which keep data together by name instead of by position.

FAQ Section: Lists

Introductory Making Lists (Concepts) - MIT Lists Chapter from MIT AI2 Online book Translatable copy of Lists Chapter from MIT AI2 Online book How to work with Lists - imagnity MIT AI2 List Blocks Help Page How to Display a List - MIT nb191 Advanced list blocks (filter, sort, map, reduce) Tables Dynamic-editable-html-table - @TimAI2 free-tableviewer-fully-style-customized-to-show-table-data (extension) - @Kevinkun Dynamic Table Layout and Table Listpicker (HTML) - @Taifun Dynamic Tab…

MIT App Inventor Dictionary Blocks

[Still_Learning]

Did you see your problem?

1. Every time you are saving to the items to global list and showing those list items alone to the listview.
2. And everytime you are wiping your own data into the tinydb in same tag.
3. If you planned to add everything then first you should know how to make a list from the existing tinydb items (that is very simple)
4. Then every time, add the current value with above tinydb list and then save that list into tinydb. This is how you should do

Please go through with the above FAQ

[Christian_Araujo]

Could you please show me the blocks, if it's not too much trouble, or if you would perhaps be kind enough to create a simple app to show me, I would really appreciate it in advance.}

Or if you prefer, I can send you my project so you can help me correct the problem, please.

Please let me know your email address if you're happy for me.

[ABG]

Here's a sample project with a similar structure.

TinyDB functions

I took a couple of hours to whip a quick and sloppy TinyDB Contact list app with dictionaries. Here's a video of it at work ... (I used my phone's screen recorder, which unfortunately does not catch cursor actions.) Designer: [Designer] Components include: A list Picker to pick Contacts from a TinyDB TagList A text box to show the current ContactName or enter a new one A Horizontal Arrangement to present a contact Attribute and its value, and allow Enter of a new value A ListView (…

I don't know if it will help, because I can't read your language and I am not sure you can read mine.

[Still_Learning]

You need to do only one thing.

During screen initialization just do this

[Christian_Araujo]

Excellent my friend, thank you very much, it works wonderfully.