How to check the Internet connection with .NET, C#, and WPF
You can try this;
private bool CheckNet()
{
bool stats;
if (System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable() == true)
{
stats = true;
}
else
{
stats = false;
}
return stats;
}
Many developers are solving that "problem" just by ping-ing Google.com. Well...? :/ That will work in most (99%) cases, but how professional is to rely work of Your application on some external web service?
Instead of pinging Google.com, there is an very interesting Windows API function called
InternetGetConnectedState()
, that recognizes whether You have access to Internet or not.
THE SOLUTION for this situation is:
using System;
using System.Runtime;
using System.Runtime.InteropServices;
public class InternetAvailability
{
[DllImport("wininet.dll")]
private extern static bool InternetGetConnectedState(out int description, int reservedValue);
public static bool IsInternetAvailable( )
{
int description;
return InternetGetConnectedState(out description, 0);
}
}
In the end I used my own code:
private bool CheckConnection(String URL)
{
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
request.Timeout = 5000;
request.Credentials = CredentialCache.DefaultNetworkCredentials;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
return true;
else
return false;
}
catch
{
return false;
}
}
An interesting thing is that when the server is down (I turn off my Apache) I'm not getting any HTTP status, but an exception is thrown. But this works good enough :)