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Periodically run a method without freezing UI.

 This was one of the requirements to periodically check if the internet connection for a system is on / off. Based on the Internet Connectivity Status, it will do certain actions. How do I check the Internet Connection Status periodically and asynchronously? 

To solve this programming puzzle (in C#.NET), I have used System.Timers.Timer class. There was one more class available in the .NET framework, that was, System.Threading.Timer. I have chosen System.Timers.Timer class, because it is thread-safe but System.Threading.Timer class isn't out of the box.

Step 1: Created an elapsed event handler for the timer class:

<Code>

// Create a timer with 10 seconds interval in the init method of the form application;
m_Timer = new System.Timers.Timer(10 * 1000);
/* It's going to fire the below-highlighted method every 10 seconds*/
m_Timer.Elapsed += checkInternetConnectionState
m_Timer.Enabled = true;

</Code>

Step 2: Created checkInternetConnectionState async method definition:

<Code>

private async void checkInternetConnectionState(Object? source, ElapsedEventArgs e)
{
    // The aqua-highlighted one actually going to do the task
    List<string>? connectDetails = await GetConnectionDetailsAsync()
}

</Code>

Step 3: Defined GetConnectionDetailsAsync  as below:

<Code>

private Task<List<string>?> GetConnectionDetailsAsync()
        {
            List<string>? connectionDetails = null;
            return Task.Run(() => {
                if ((Microsoft.WindowsAPICodePack.Net.
                        NetworkListManager.IsConnectedToInternet))
                {
                    NetworkCollection netCollection = 
                        NetworkListManager.
                        GetNetworks(NetworkConnectivityLevels.Connected);
                    connectionDetails = new List<string>();
                    foreach (Network net in netCollection)
                    {
                        if (net.IsConnected)
                        {
                            connectionDetails.Add(net.Name);
                            connectionDetails.Add(net.Category.ToString());
                            connectionDetails.Add(net.DomainType.ToString());
                            connectionDetails.Add(net.ConnectedTime.ToString());
                        }
                    }
                }
                return connectionDetails;
            });
        }

</Code>

I have used WindowsAPICodePack to get internet connectivity status and details. If we stitch these three steps together we can achieve the desired goal. 

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