StringBuilder sb = new StringBuilder();
sb.Append("<Method ID='1' Cmd='Update'>");
sb.Append(String.Format("<Field Name=\"ID\">" + id_value + "</Field>"));
sb.Append(String.Format("<Field Name=\"FileRef\">" + URL +"</Field>"));
sb.Append("</Method>");

System.Xml.XmlElement elBatch = xmlDoc.CreateElement("Batch");
elBatch.SetAttribute("OnError", "Continue");
elBatch.SetAttribute("PreCalc", "TRUE");
elBatch.SetAttribute("ListVersion", "1");
elBatch.SetAttribute("ViewName", "view_id without '{}' braces");
elBatch.InnerXml = sb.ToString();

XmlNode ndReturn = client.UpdateListItems(ListID, elBatch);