Load page then process rows in Asp.net - asp.net

Question

I have a webpage that is a site monitoring tool for my company. Basically, it pulls a list of 150 IP addresses from a database, and checks if the webpage loads for them. This takes about 15 minutes to load, I'd like it to load the list and go 1 by 1 and update the status with text or an icon.
Here is my Function block, any way to thread this or help me get to what I need to get to?
Function SiteMonitorResults(ByVal WebAddress As String)
Try
'Code Example
Dim httpReq As HttpWebRequest = DirectCast(WebRequest.Create(WebAddress), HttpWebRequest)
httpReq.AllowAutoRedirect = False
Dim httpRes As HttpWebResponse = DirectCast(httpReq.GetResponse(), HttpWebResponse)
' Close the response.
httpRes.Close()
' Code for NotFound resources goes here.
If httpRes.StatusCode = HttpStatusCode.OK Then
Return "Online"
Else
Return "Offline"
End If
Catch ex As Exception
Return "Unknown"
End Try
End Function

Answer 1

Basically, I would go for something like this, using System.Threading.Tasks and System.Net.Http
( sorry for C# code )
I left out try catch for readability, but they are required, or the code will crash on the first DNS problem (for example)
public string CheckAddresses(List<string> addresses)
{
List<string> result = new List<string>();
List<Task> tasks = new List<Task>();
addresses.ForEach(address =>
{
var task = new HttpClient().GetAsync(address).ContinueWith(
res => result.Add(String.Format("{0} : {1}", address, res.Result.IsSuccessStatusCode)));
tasks.Add(task);
});
Task.WaitAll(tasks.ToArray());
return string.Join(", ", result.ToArray());
}
Hope this will help