C# xml 读取 编辑保存 新增保存 查找是否存在特定节点

XmlDocument document = new XmlDocument();
document.Load("Config.xml");

XmlNodeList list = document.SelectNodes("/configuration/SysSettings/Item");

ID = document.SelectSingleNode("/SmsSet/ID").InnerText.Trim();

string att = item.Attributes["name"].Value.ToString();

node.Attributes["runflag"].Value = "0";
document.Save("Config.xml");

XmlNode pnode = document.SelectSingleNode("/configuration/SysSettings");
XmlElement xe = document.CreateElement("Item");
xe.SetAttribute("id", id);
xe.SetAttribute("name", this.ItemName.Text.ToString().Trim());
xe.SetAttribute("dllpath", this.DLLName.Text.ToString().Trim());
xe.SetAttribute("space", this.SpaceName.Text.ToString().Trim());
pnode.AppendChild(xe);
document.Save("Config.xml");

XmlNode same = document.SelectSingleNode("//Item[@name='北京']");//查找