B4X:
Private Sub ReadListAsync(dir As String, arq As String) As ResumableSub
Dim l As List
l.Initialize
Dim Reader As TextReader
Reader.Initialize(File.OpenInput(dir, arq))
Dim i As Int
Dim line As String
line = Reader.ReadLine
Do While line <> Null
i = i + 1
l.Add(line)
If i = 1000 Then
Sleep(1)
i = 0
End If
line = Reader.ReadLine
Loop
Reader.Close
Return l
End Sub