Android Question SaveAs - What is the explanation ?

I don't see any reason for the behavior you describe. My guess is that the problem is somewhere else.

If you are able to reproduce it in a small project then we can check it.

In the release version, if I don't change, inside SaveAs, the name of the file, that is, I leave saida.pdf, it saves correctly.
For this reason I don't believe it is something in the program itself.
I will try to build a small project.

Erel,
I found an explanation: my tests were being done on an android 6 device.
I did the tests on a device with android 12 and the release version worked perfectly.
Is the SaveAs "function" restricted for some Android versions ?

The SaveAs code should work on Android 5+. The exact behavior depends on the OS.

If this is a blocking issue then use it on Android 7+ and directly access the file system on Android 6- (you need the runtime external storage permission).

The strange problem I reported in the initial message happened because I was using a Chinese version smartphone with a modified Android 6 rom.?
Later I tested the "SaveAs" function on smartphones and tablets with Android versions 5, 6, 7, 8, 11 and 12 and the routine worked perfectly.
The only caveat to be made is that when, using "SaveAs", a file called test.pdf, for example, is saved and then we save another file with the same name, it is saved as test.pdf(1).
This fact causes the second file to no longer be automatically recognized as a pdf file as the pdf(1) extension is not the default for pdf. The desirable thing is that it was saved as test(1).pdf
Obviously this happens with all types of files.
But this is not quite a problem.

Also try to add Sleep(1000) code before SaveAs command.
Sleep function sometime solves the problems between fast consecutive file operations.