(VB.NET) File Existence Check

Testing to see if a file exists on the FTP server. The GetSizeByName method is a convenient way to check if a file exists. It will return -1 if the file does not exist, otherwise it returns the size of the file in bytes.

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

Dim ftp As New Chilkat.Ftp2

ftp.Hostname = "ftp.example.com"
ftp.Username = "username"
ftp.Password = "password"

' Connect and login to the FTP server.
Dim success As Boolean = ftp.Connect()
If (success <> True) Then
    Debug.WriteLine(ftp.LastErrorText)
    Exit Sub
End If


' Set the current remote directory to where the file is located:
success = ftp.ChangeRemoteDir("something")
If (success <> True) Then
    Debug.WriteLine(ftp.LastErrorText)
    Exit Sub
End If


' Test to see if the file exists by getting the file size by name. 
' If a -1 is returned, the file does not exist.
Dim fileSize As Integer = ftp.GetSizeByName("test123.txt")
If (fileSize < 0) Then
    Debug.WriteLine("file does not exist")
Else
    Debug.WriteLine("file exists and is " & fileSize & " bytes in size")
End If


success = ftp.Disconnect()