What does this code mean (s, e)?

Question

How does this code work?

      app.InstallStateChanged += (s, e) => UpdateUI();
      NetworkChange.NetworkAddressChanged +=
            (s, e) => UpdateNetworkIndicator();

Can someone please unscramble this?

The code comes from an example used in a silverlight 4 OOB systems http://msdn.microsoft.com/en-us/library/dd833066(v=VS.95).aspx

UpdateNetworkIndicator does not return anything. UpdateUI does not return anything.

Answer 1

This is a lambda expression that contains multiple parameters. In this case (as you are using the function to replace an event handler) they are equivalent to the object and EventArgs parameters.

Your code is equivalent to the below

app.InstallStateChanged += OnInstallStateChanged;
NetworkChange.NetworkAddressChanged += OnNetworkAddressChanged;

/* ... */

private void OnInstallStateChanged(object s, EventArgs e)
{
    UpdateUI();
}

private void OnNetworkAddressChanged(object s, EventArgs e)
{
    UpdateNetworkIndicator();
}