MATLAB app designer ( import data using a dialog box , working with Text Area and Text Edit Field ) 

I got the same warning, "Unrecognized function or variable 'file'."

Try the below code: [file,path,indx] = uigetfile({'*.xlsx'},'Select the Excel file'); filename = fullfile(path, file); measured_results = importdata(filename)

That is probably because you need the file path in the next lines of your code. in that case define a parameter and set it to 0 originally. only if there is a file path change that parameter to 1. put he rest part of your code in an if function with the condition that if that parameter is 1, run the rest part of your code where the file path is needed. I don't know if this help or not but you may try it.

This link may help you: se.mathworks.com/help/database/ug/databaseexplorer-app.html

@@HVE got the solution it was a reference that wasn't long enough to include the condition I needed thank you for helping me

Make sure that you are in the right directory.

Yes, I'm exactly in the same directory than the GUI but still not able to choose other type of files than Matlab files...

@@shridevisandiramourty7167 From MATLAB main interface try to import some data, using the import data button. Select all files and see if you can see the text files in your directory.

@@HVE thanks a lot for your quick response. Finally I used uigetfile('*.csv') and that works for me because I only need csv files as input.