I was looking for help on copying data from Dir.Internal to an SD Card using the ExternalStorage class and noticed a few other people couldn't quite get to grips with it either. So for them here's an example, which works for me. Took me a while to get something to work, but got there eventually. Works for me anyway.
Remember you'll need the ExternalStorage class. You can get it by searching the forum.
B4X:
Try
Storage.SelectDir(False)
Wait For Storage_ExternalFolderAvailable
Dim lFileName As String="test.db"
Dim InputStream1 As InputStream
InputStream1 = File.OpenInput(File.Dirinternal, lFileName)
Dim lFile As ExternalFile
lFile=Storage.CreateNewFile(Storage.root,lFileName)
Dim outputstream1 As OutputStream
outputstream1= Storage.OpenOutputstream(lFile)
File.copy2(InputStream1,outputstream1)
InputStream1.Close
outputstream1.close
Msgbox2("Database copied. File Name: "&lFileName,"Info","OK","","",Null)
Catch
Log(LastException)
End TryRemember you'll need the ExternalStorage class. You can get it by searching the forum.