Windows Service restarts on Exception

Question

I'm building a windows service that grabs information from a website periodically How can I start looking again when a exception is caught? for example when internet goes down and up later.

Code:

public string cadena(string pagina)
        {
            try
            {
                String cadena;
                WebRequest myWebRequest = WebRequest.Create(pagina);
             myWebrequest = 10000;
                WebResponse myWebResponse = myWebRequest.GetResponse();
                Stream ReceiveStream = myWebResponse.GetResponseStream();
                Encoding encode = System.Text.Encoding.GetEncoding("ISO-8859-1");
                StreamReader readStream = new StreamReader(ReceiveStream, encode);
                cadena = readStream.ReadToEnd();
                readStream.Close();
                myWebResponse.Close();
                return cadena;
            }
            catch (WebException error)
            {
                myTimer.Enabled = true;
                return "error";
            }
        }
public void inicia(object sender, System.Timers.ElapsedEventArgs e)
        {
                myTimer.Enabled = false;
                String strSite = cadena("www.something.com");
                //Do something with strSite...
                myTimer.Enabled = true;            
        }
    protected override void OnStart(string[] args)
            {           
                    myTimer = new System.Timers.Timer();                    
                    myTimer.Interval = 1500;         
                    myTimer.Elapsed += new System.Timers.ElapsedEventHandler(inicia);      
                    myTimer.Enabled = true;            
            }

Answer 1

Here is a very crude example to get you started, this will keep your program from continuing until you get a valid response. There are better ways of doing this, but this is the idea you want. Good luck!

myWebResponse = myWebRequest.GetResponse();
while (myWebResponse.ContentLength == -1) {  
  //sleep
 myWebResponse = myWebRequest.GetResponse();
}  

//continue execution

You should probably put in a check to see if the remote site is available, and either poll until it is, or interrupt when the service is available. This way you won't have to recover from a thrown exception.

I think using exceptions should be reserved for things a little more catastrophic to your application.