关于C#引发事件！解决思路

关于C#引发事件！！！！
namespace 引发事件
{
    public class AddressChangedEventArgs
    {
        private object data;
        public AddressChangedEventArgs(object data)
        {
            this.data = data;
        }
        public object Data
        {
            get { return data; }
        }
    }
   public class CustomEventArgs:System.EventArgs
   {
       private object data;
       public CustomEventArgs(object data)
       {
           this.data = data;
       }
       public object Data
       {
           get{return data;}
       }
   }

   public class Contact
   {
       public event EventHandler<AddressChangedEventArgs> AddressChanged;
       private string address;
       protected virtual void onAddressChanged(AddressChangedEventArgs e)
    {
        EventHandler<AddressChangedEventArgs> handler = AddressChanged;
           
           if(handler!=null) 
           {
               handler(this,e);
           }
      }
       public string Address
       {
           get { return this.address; }
           set
        {
               this.address  = value;
               AddressChangedEventArgs args = new AddressChangedEventArgs(this.address);
               onAddressChanged(args);
        }
     }
  }
 
 
}




------解决思路----------------------
AddressChangedEventArgs要从EventArgs继承