How to check if Internet Connection Available through Dot Net Code

Checking whether an Internet connection is available isn’t always as easy as it sounds.
Admittedly, there is a Windows API call that can check whether a connection exists, but it’s extremely fragile and returns incorrect results if the machine has never had Internet Explorer configured correctly. Oops.

The best method is to actually make a Web request and see whether it works. If it does, you’ve got your connection. The following neat code snippet does exactly that. Just call IsConnectionAvailable and check the return value:

Public Function IsConnectionAvailable() As Boolean
' Returns True if connection is available
' Replace www.yoursite.com with a site that
' is guaranteed to be online - perhaps your
' corporate site, or microsoft.com
Dim objUrl As New System.Uri("http://www.yoursite.com/")
' Setup WebRequest
Dim objWebReq As System.Net.WebRequest
objWebReq = System.Net.WebRequest.Create(objUrl)
Dim objResp As System.Net.WebResponse
Try
' Attempt to get response and return True
objResp = objWebReq.GetResponse
objResp.Close()
objWebReq = Nothing
Return True
Catch ex As Exception
' Error, exit and return False
objResp.Close()
objWebReq = Nothing
Return False
End Try

Here’s how you might use this function in your application:

If IsConnectionAvailable() = True Then
MessageBox.Show("You are online!")
End If