xml读写

吾乃xml大白，最近用于项目要更改程序配置文件，最终以xml读写方式进行。

插叙：xml简单介绍http://www.cnblogs.com/jb8164/articles/736515.html；

更改值，如没有对应的key，进行新建。

 private void ModifyXML(string path,string NodeName,string AppKey,string AppValue)
        {
            try
            {
                System.Xml.XmlDocument xDoc = new System.Xml.XmlDocument();
                xDoc.Load(path);

                System.Xml.XmlNode xNode;
                System.Xml.XmlElement xElem1;
                System.Xml.XmlElement xElem2;
                xNode = xDoc.SelectSingleNode("//" + NodeName);

                xElem1 = (System.Xml.XmlElement)xNode.SelectSingleNode("//add[@key='" + AppKey + "']");

                string p1 = xElem1.GetAttribute("value");

                if (xElem1 != null) xElem1.SetAttribute("value", AppValue);
                else
                {
                    xElem2 = xDoc.CreateElement("add");
                    xElem2.SetAttribute("key", AppKey);
                    xElem2.SetAttribute("value", AppValue);
                    xNode.AppendChild(xElem2);
                }
                xDoc.Save(path);
            }
            catch (Exception ex)
            {
            }
        }

获取值

private string ReadXML(string path, string NodeName, string AppKey)
        {
            try
            {
                System.Xml.XmlDocument xDoc = new System.Xml.XmlDocument();
                xDoc.Load(path);

                System.Xml.XmlNode xNode;
                System.Xml.XmlElement xElem1;
                System.Xml.XmlElement xElem2;
                xNode = xDoc.SelectSingleNode("//" + NodeName);

                xElem1 = (System.Xml.XmlElement)xNode.SelectSingleNode("//add[@key='" + AppKey + "']");
                return xElem1.GetAttribute("value");
            }
            catch (Exception ex)
            {
                return "";
            }
        }

目前停留在基础应用，现学现卖。感觉xml这种树形结构，关键在于结构的组织，对节点的索引和节点内容的规范。