将文件保存在/ Download下，其名称为/ storage / emulated / 0 / Download。 有时文件无法访问

Question

On my Samsung devices I put a file in the /Download folder. When I select the file within my app (via a file browser), the file is called /storage/emulated/0/Download/myfile.db . This name is stored in my app settings.

At the start of the app the file should be opened. First the app checks if the file exists. In some cases, say once every 2 weeks, the file is said to be not existing! This happens also at my friends mobile since half a year.

Why is that happening? For years everything ran smoothly.

This code runs for 6 years. Of course I added the permissions stuff.

Your help is much appreciated!

Answer 1

You can't use the Download as an guaranteed storage place for your files. You should use the Internal storage for the app. This is what Google has written about the download folder:

This space is called external because it's not guaranteed to be accessible—it is a storage space that users can mount to a computer as an external storage device, and it might even be physically removable.

Here you can read more about the Internal storage and the External storage in Android.

Here is some more information about the Download folder from Google.

Caution: The external storage might become unavailable if the user removes the SD card or connects the device to a computer. And the files are still visible to the user and other apps that have the READ_EXTERNAL_STORAGE permission. So if your app's functionality depends on these files or you need to completely restrict access, you should instead write your files to the internal storage .