Event Signature in .NET — Using a Strong Typed 'Sender'? [closed]

Answer 1

Looking back to blasphemy as the only reason for making sender an object type (if to omit problems with contravariance in VB 2005 code, which is a Microsoft's blunder IMHO), can anyone suggest at least theoretical motive for nailing the second argument to EventArgs type. Going even further, is there a good reason to conform with Microsoft's guidelines and conventions in this particular case?

Having need to develop another EventArgs wrapper for another data that we want to pass inside event handler seems odd, why can't straightly pass that data there. Consider the following sections of code

[Example 1]

public delegate void ConnectionEventHandler(Server sender, Connection connection);

public partial class Server
{
    protected virtual void OnClientConnected(Connection connection)
    {
        if (ClientConnected != null) ClientConnected(this, connection);
    }

    public event ConnectionEventHandler ClientConnected;
}

[Example 2]

public delegate void ConnectionEventHandler(object sender, ConnectionEventArgs e);

public class ConnectionEventArgs : EventArgs
{
    public Connection Connection { get; private set; }

    public ConnectionEventArgs(Connection connection)
    {
        this.Connection = connection;
    }
}

public partial class Server
{
    protected virtual void OnClientConnected(Connection connection)
    {
        if (ClientConnected != null) ClientConnected(this, new ConnectionEventArgs(connection));
    }

    public event ConnectionEventHandler ClientConnected;
}