protected void bSaveClose_Click(object sender, EventArgs e)
{
 foreach (ListViewDataItem litem in lvList.Items)
        {
            HiddenField hdId = litem.FindControl("hdId") as HiddenField;  //ID записи
            ImageButton imgEdit = litem.FindControl("imgEdit") as ImageButton;  //Иконка редактирования в ListView

            if (hdId != null)
            {
                if (Int64.Parse(hdId.Value) == IdI)  // id записи в ViewState
                {
                    imgEdit.Enabled = false;
                    imgEdit.ImageUrl = "~/Images/Saved.png";
                    DataSave.InsData(Int64.Parse(hdId.Value));  //Ф-я сохранения данных в базе - пример
                    //return;
                }
            }
        }
}

protected void lstList_ItemDataBound(object sender, ListViewItemEventArgs e)
    {
        if (e.Item.ItemType == ListViewItemType.DataItem)
        {
            HiddenField hdId = e.Item.FindControl("hdId") as HiddenField;
            ImageButton imgEdit = e.Item.FindControl("imgEdit") as ImageButton;
            if (Int64.Parse(hdId.Value) == IdI)  //IdI - id записи в ViewState
            {
                imgEdit.Enabled = false;
                imgEdit.ImageUrl = "~/Images/Saved.png";
            } 
        }
    }

private Int64 IdI
    {
        set { ViewState["idi"] = value; }
        get { return (ViewState["idi"] != null ? (Int64)ViewState["idi"] : 0); }
    }

 protected void bEdit_Command(object sender, CommandEventArgs e)
{
   pnlEdit.Visible = true;  // контрол Panel с полями редактирования TextBox И т. д.
   ....
  foreach (ListViewDataItem litem in lvList.Items)
  {
      HiddenField hdId = litem.FindControl("hdId") as HiddenField;
      .....
      if (hdId != null)
            {
                if (hdId.Value == e.CommandArgument.ToString())
                {
                    IdI = Int64.Parse(hdId.Value);
                    ......
                }
            }
  }
}