(VB.NET) Get Size of File on Web Server

Demonstrates how to send a HEAD request to fetch information about a file on a web server, which hopefully includes the Content-Length in the response header.

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://nodejs.org/dist/v10.16.1/node-v10.16.1-win-x64.zip")
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:

' Date: Thu, 01 Aug 2019 12:47:27 GMT
' Content-Type: application/zip
' Content-Length: 17457922
' Connection: keep-alive
' Set-Cookie: __cfduid=da5b78dcdd8171683c5a578eb9c9f88c81564663647; expires=Fri, 31-Jul-20 12:47:27 GMT; path=/; domain=.nodejs.org; HttpOnly
' Last-Modified: Wed, 31 Jul 2019 18:21:57 GMT
' ETag: "5d41dc45-10a6302"
' Accept-Ranges: bytes
' Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
' Server: cloudflare
' CF-RAY: 4ff7ebb32ac4e1e2-ORD

' Get the Content-Length header.
Dim contentLengthStr As String = resp.GetHeaderField("Content-Length")
' If the header exists...
If (resp.LastMethodSuccess = True) Then
    Debug.WriteLine("Content-Length: " & contentLengthStr)
    ' Your application can convert the contentLengthStr to an integer and then use it....
End If