Passing multiple parameters in DataEventArgs
public class MyEventsArgs:EventArgs
{
     public MyEventsArgs()
     {

     }

     public int prop1 { get; set; }
     public int prop2 { get; set; }
     public int prop3 { get; set; }
}

yourUI1.YourEvent += new EventHandler(hndlr);

public void hndlr(object obj, EventArgs args)
{
    MyEventsArgs myArgs = (MyEventsArgs)args;
}