[c#]
internal class MyGrid : FlyGrid
{
  public MyGrid()
  {
  }
  protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
  {
    bool res = base.ProcessCmdKey(ref msg, keyData);
    if (keyData == Keys.Return)
    {
      if (ActiveRootPort.EndEdit(true))//commit changes
      {
        MyNode newNode = new MyNode(new object[] { 1, DateTime.Now });
        ActiveRootPort.Rows.Items.Add(newNode);

        this.Selected = newNode;
        return true;
      }
    }
    return base.ProcessCmdKey(ref msg, keyData);    
  }
}

[c#]
internal class MyGrid : FlyGrid
{
  public MyGrid()
  {
  }
  protected override bool CommitText(FlyGridViewPort port, string text)
  {
    bool res = base.CommitText(port, text);
    if (res)
    {
      MyNode newNode = new MyNode(new object[] { 1, DateTime.Now });
      port.Rows.Items.Add(newNode);
      this.Selected = newNode;
    }
    return res;
  }
}

[c#]
bool res = base.CommitText(port, text);