(VBScript) Asynchronous FTP Download

The Chilkat FTP component supports asynchronous uploads and downloads. This examples demonstrates doing a download in a background thread. The download is started by calling AsyncGetFileStart. While the download is in progress, your program may do other tasks. You may periodically check the AsyncFinished property to determine when the transfer is finished. The example below provides the remainder of the details.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
Set outFile = fso.CreateTextFile("output.txt", True)

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

set ftp = CreateObject("Chilkat_9_5_0.Ftp2")

ftp.Hostname = "ftp.myftpserver.com"
ftp.Username = "test"
ftp.Password = "test"

' Connect and login to the FTP server.
success = ftp.Connect()
If (success <> 1) Then
    outFile.WriteLine(ftp.LastErrorText)
    WScript.Quit
End If

localFilename = "hamlet.xml"
remoteFilename = "hamlet.xml"

' Begin the download in a background thread.
' Only 1 background upload or download may be active at any time.
' (per instance of an FTP object)
success = ftp.AsyncGetFileStart(remoteFilename,localFilename)
If (success <> 1) Then
    outFile.WriteLine(ftp.LastErrorText)
    WScript.Quit
End If

' The application is now free to do anything else
' while the file is downloading.
' For this example, we'll simply sleep and periodically
' check to see if the transfer if finished.  While checking
' however, we'll report on the progress in both number
' of bytes tranferred and performance in bytes/second.
Do While ftp.AsyncFinished <> 1

    outFile.WriteLine(ftp.AsyncBytesReceived & " bytes received")
    outFile.WriteLine(ftp.DownloadTransferRate & " bytes per second")

    ' Sleep 1 second.
    ftp.SleepMs 1000

Loop
outFile.WriteLine(ftp.AsyncBytesReceived & " total bytes received")
outFile.WriteLine(ftp.DownloadTransferRate & " final bytes per second")

' Did the download succeed?
If (ftp.AsyncSuccess = 1) Then
    outFile.WriteLine("File Downloaded!")
Else
    ' The error information for asynchronous ops
    ' is in AsyncLog as opposed to LastErrorText
    outFile.WriteLine(ftp.AsyncLog)
End If

success = ftp.Disconnect()

outFile.Close