(VB.NET) Get the Last-Modified Date Before HTTP Download

Demonstrates how to send a HEAD request to get the last-modified date of a file on a web server (without downloading the file).

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim http As New Chilkat.Http

Dim resp As Chilkat.HttpResponse = http.GetHead("https://www.chilkatsoft.com/hamlet.xml")
If (http.LastMethodSuccess = False) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


' Examine the response header.
Debug.WriteLine(resp.Header)

' Here is a sample response header:

' 	Content-Length: 279658
' 	Content-Type: text/xml
' 	Last-Modified: Thu, 12 May 2016 15:14:08 GMT
' 	Accept-Ranges: bytes
' 	ETag: "c1cd8bee60acd11:0"
' 	Server: Microsoft-IIS/8.5
' 	X-Powered-By: ASP.NET
' 	X-Powered-By-Plesk: PleskWin
' 	Date: Thu, 25 Jul 2019 16:40:54 GMT

' Get the Last-Modified header.
Dim lastModStr As String = resp.GetHeaderField("Last-Modified")
' If the header exists...
If (resp.LastMethodSuccess = True) Then
    ' Parse the RFC822 format date/time string
    Dim ckdt As New Chilkat.CkDateTime
    ckdt.SetFromRfc822(lastModStr)

    ' If we want to access individual date/time parts (in the local timezone)
    Dim dt As Chilkat.DtObj = ckdt.GetDtObj(True)
    Debug.WriteLine("day/month/year = " & dt.Day & "/" & dt.Month & "/" & dt.Year)

End If