Lists, two-dimensional arrays, indexes and passing parameters

MIT App Inventor Help
1

Hi, I'm trying to load a list of items from a spreadsheet into listview, which I can do successfully. The spreadsheet has two columns; Column 1 is the description of the item as seen on the screen in the list, which can be several words. For example, "Invalid bar codes", and the second column has an abbreviation of that that I want to use as a key for a second spreadsheet, eg, "Invalid".

I know I have successfully loaded both columns into two different lists, ShowData and HideData, as either of them can be selected to be loaded into listview. But what I want is that when an item is selected in listview, the 'HideData' entry corresponding to the selected entry in Listview is passed to the next screen. Eg, when they select item 'Invalid Bar Codes' which is item 7 from the list on the screen which comes from 'Showdata', I want 'Invalid' which is item 7 in HideData passed as a parameter to the next screen. (note: the hidden column is not necessarily just the first word of the shown column). I can't work out how to identify the corresponding entry in the other list of the one selected on the screen.

Can anyone help? Any advice gratefully received.
Thanks,
Mike

2

if both lists are "paired", that is, if you choose element 3 from the first list, you want element 3 from the second list, you can get the index of the element from the first list (may be SelectionIndex from the ListView), choose that same element from the second list and pass it to the second screen (open another screen with start value)

3

Thanks, I'd really appreciate if you could show me how the blocks are arranged. I've been faffing about with this and I can't seem to get it to work.

4

screen1
screen1782×344 23.1 KB

you can get the passed value in Screen 2 with
controls_getStartValue

1 Like
5

There is a Lookup In Pairs block that works well with two column tables.

Also, stacked Vertical Arrangements (one Visible at a time) can share data much easier than different Screens.

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