Hi Power-Apps community,
I have another challenge I am not able to solve by myself and therefore kindly ask for your help.
Overall use case:
I am using the OOTB-Inventory App to track my inventory stocks. All of the displayed values in the App come from a SP List called 'Inventory List'.
I now want to improve the inventory App by a separate mobile App called QR-Code Scanner. Its goal is to easily update withdrawals or restockings of items.
Specific use case for the QR-Code Scanner:
Within my warehouse each product has a unique product code that is stored in a QR code. My users are to update the inventory list immediately whenever they are restocking or withdrawing items from the warehouse. To do that I have created a mobile App that uses the barcode-Scanner control to scan a QR codes. The QR code contains the unique product ID. By scanning the QR code this product ID is extracted and stored in a collection called Coll_multiscan. This collection, Coll_multiscan, is run against another collection called Coll_Products. Coll-Products is the Collection containing all of the data of the SP List 'Inventory List', to check for the ID and look up all the column details (e.g. name, current quantity) from the SP list.
The scanned items are then displayed in a gallery, that does not only show the Product ID but also the name and the current quantity to add user friendliness. And now I run into the catch:
My goal is to make the App as user friendly as possible. The user is supposed to work with on hand only, no typing necessary. So this is why I want to introduce the slider.
I have added sliders to the gallery items. There the user can either slide to the right to add the amount of items he has added or slide to the left to reduce the stock. I then want to patch these individual selections to the collection Coll_Products to update the quantities.
To do that I use the following formula:
ForAll(RenameColumns(Filter(ProductCollect,ID in Coll_Multiscan.Barcode_Info),"ID","EID"),Patch(ProductCollect,LookUp( ProductCollect ,ID=EID),{'Curent Quantity':Slider5.Value}))
What happens then though is that not the individual slider values get passed but only the lastly selected slider value gets patched to all selected items. So if I have 2 items in the gallery and the individual selected values are
1. +4
2. -3,
-3 will be patched as all three quantities.

Anyone being able to help me?
Thank you and best regards
JHL