title: Checked If there is Connection to SQL Server or not in WPF
body: <p>My WPF application connected to SQL Server database via a connection string in <code>App.config</code> and it works over local network.</p>
  
  <p>I have a login screen "4 PassCode digit Login", after enter the fourth digit I checked "As usual" if true or not.</p>
  
  <p>My question here how can I check if client machine has connection to the server or not? If not I want to show message.</p>
  
  <p>I don't know from where should I start :(</p>
  
  <p>Hope this clear.
  Thanks</p>