How to create file name list from a folder/directory

[Sfazist]

Dear Fellows,

I am working on an image app. I am using TinyDB to store image location.I have implemented a delete function in the app as well which deletes file from its location and also clearTag from TiyDB. My problem is, when user deletes images from image location (folder/directory) without using application image delete function (e.g. by using any file manager etc.) TinyDB sill contains its Tag alive.  

One solution could be a list of existing files from image location (folder/directory) and this could help to find images which is present in TinyDB tags but it has been deleted from image location (folder/directory). So, how to create file name list from a folder/directory?:)

[Stephen Zipprich]

Why not have a check when your application loads if the file still exists, and if not, delete the tag from TinyDB?

[Sfazist]

Thanks Stephen,

you are right, it should be checked during initialization time of application. Let me explain a bit more

1. Its not a single file. it could be more number of files deleted by user without using app delete function.
   
2. Application has a list of all DBTags. i have to compare this list with existing files in a folder/directory.

Any way, how can i find that a file eg. test.png  exist in /imagefolder/ or not. 

[Taifun]

So, how to create file name list from a folder/directory?

App Inventor does not offer a feature to get a list of filenames of a directory

a workaround is to call a terminal emulator app using the activity starter and store the result in a file, then read the file using the file component

How to execute statements in the Jackpal Terminal Emulator

the statement to execute could be something like this (assuming you want to list all files in directory /mnt/sdcard/Music including all subdirectories)

ls -R /mnt/sdcard/Music > /mnt/sdcard/myResult.txt && exit

Taifun

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