在.net的項目開發中，經常會對XML文件進行操作，由於XML文件可以實現跨平台傳輸，較多的應用在數據傳輸中，特總結以下幾種常用的XML操作方法：
1.創建XML文檔：
/// <summary>
/// 創建XML文檔
/// </summary>
/// <param name="name">根節點名稱</param>
/// <param name="type">根節點的一個屬性值</param>
/// <returns>XmlDocument對象</returns>
public static XmlDocument CreateXmlDocument(string name, string type)
{
XmlDocument doc;
try
{
doc = new XmlDocument();
doc.LoadXml("<" + name + "/>");
var rootEle = doc.DocumentElement;
rootEle?.SetAttribute("type", type);
}
catch (Exception er)
{
throw new Exception(er.ToString());
}
return doc;
}
2.讀取XML文檔中的數據：
/// <summary>
/// 讀取數據
/// </summary>
/// <param name="path">路徑</param>
/// <param name="node">節點</param>
/// <param name="attribute">屬性名，非空時返回該屬性值，否則返回串聯值</param>
/// <returns>string</returns>
public static string Read(string path, string node, string attribute)
{
var value = "";
try
{
var doc = new XmlDocument();
doc.Load(path);
var xn = doc.SelectSingleNode(node);
if (xn != null && xn.Attributes != null)
value = (attribute.Equals("") ? xn.InnerText : xn.Attributes[attribute].Value);
}
catch (Exception er)
{
throw new Exception(er.ToString());
}
return value;
}
3.對XML文檔插入數據：
/// <summary>
/// 插入數據
/// </summary>
/// <param name="path">路徑</param>
/// <param name="node">節點</param>
/// <param name="element">元素名，非空時插入新元素，否則在該元素中插入屬性</param>
/// <param name="attribute">屬性名，非空時插入該元素屬性值，否則插入元素值</param>
/// <param name="value">值</param>
/// <returns></returns>
public static void Insert(string path, string node, string element, string attribute, string value)
{
try
{
var doc = new XmlDocument();
doc.Load(path);
var xn = doc.SelectSingleNode(node);
if (element.Equals(""))
{
if (!attribute.Equals(""))
{
var xe = (XmlElement)xn;
xe?.SetAttribute(attribute, value);
//xe?.SetAttribute(attribute, value);
}
}
else
{
var xe = doc.CreateElement(element);
if (attribute.Equals(""))
xe.InnerText = value;
else
xe.SetAttribute(attribute, value);
xn?.AppendChild(xe);
}
doc.Save(path);
}
catch (Exception er)
{
throw new Exception(er.ToString());
}
}
4.修改XML文檔中的數據：
/// <summary>
/// 修改數據
/// </summary>
/// <param name="path">路徑</param>
/// <param name="node">節點</param>
/// <param name="attribute">屬性名，非空時修改該節點屬性值，否則修改節點值</param>
/// <param name="value">值</param>
/// <returns></returns>
public static void Update(string path, string node, string attribute, string value)
{
try
{
var doc = new XmlDocument();
doc.Load(path);
var xn = doc.SelectSingleNode(node);
var xe = (XmlElement)xn;
if (attribute.Equals(""))
{
if (xe != null) xe.InnerText = value;
}
else
{
xe?.SetAttribute(attribute, value);
}
doc.Save(path);
}
catch (Exception er)
{
throw new Exception(er.ToString());
}
}
5.刪除XML文檔中數據：
/// <summary>
/// 刪除數據
/// </summary>
/// <param name="path">路徑</param>
/// <param name="node">節點</param>
/// <param name="attribute">屬性名，非空時刪除該節點屬性值，否則刪除節點值</param>
/// <returns></returns>
public static void Delete(string path, string node, string attribute)
{
try
{
var doc = new XmlDocument();
doc.Load(path);
var xn = doc.SelectSingleNode(node);
var xe = (XmlElement)xn;
if (attribute.Equals(""))
{
xn?.ParentNode?.RemoveChild(xn);
}
else
{
xe?.RemoveAttribute(attribute);
}
doc.Save(path);
}
catch (Exception er)
{
throw new Exception(er.ToString());
}
}
6.讀取XML文檔中指定節點數據：
/// <summary>
/// 獲得xml文件中指定節點的節點數據
/// </summary>
/// <param name="path"></param>
/// <param name="nodeName"></param>
/// <returns></returns>
public static string GetNodeInfoByNodeName(string path, string nodeName)
{
var xmlString = string.Empty;
try
{
var xml = new XmlDocument();
xml.Load(path);
var root = xml.DocumentElement;
if (root == null) return xmlString;
var node = root.SelectSingleNode("//" + nodeName);
if (node != null)
{
xmlString = node.InnerText;
}
}
catch (Exception er)
{
throw new Exception(er.ToString());
}
return xmlString;
}
7.獲取XML指定節點的屬性：
/// <summary>
/// 功能:讀取指定節點的指定屬性值
/// </summary>
/// <param name="path"></param>
/// <param name="strNode">節點名稱</param>
/// <param name="strAttribute">此節點的屬性</param>
/// <returns></returns>
public string GetXmlNodeAttributeValue(string path, string strNode, string strAttribute)
{
var strReturn = "";
try
{
var xml = new XmlDocument();
xml.Load(path);
//根據指定路徑獲取節點
var xmlNode = xml.SelectSingleNode(strNode);
if (xmlNode != null)
{
//獲取節點的屬性，並循環取出需要的屬性值
var xmlAttr = xmlNode.Attributes;
if (xmlAttr == null) return strReturn;
for (var i = 0; i < xmlAttr.Count; i++)
{
if (xmlAttr.Item(i).Name != strAttribute) continue;
strReturn = xmlAttr.Item(i).Value;
break;
}
}
}
catch (XmlException xmle)
{
throw new Exception(xmle.Message);
}
return strReturn;
}
8.設置XML文檔中指定節點的屬性：
/// <summary>
/// 功能:設置節點的屬性值
/// </summary>
/// <param name="path"></param>
/// <param name="xmlNodePath">節點名稱</param>
/// <param name="xmlNodeAttribute">屬性名稱</param>
/// <param name="xmlNodeAttributeValue">屬性值</param>
public void SetXmlNodeAttributeValue(string path, string xmlNodePath, string xmlNodeAttribute, string xmlNodeAttributeValue)
{
try
{
var xml = new XmlDocument();
xml.Load(path);
//可以批量為符合條件的節點的屬性付值
var xmlNode = xml.SelectNodes(xmlNodePath);
if (xmlNode == null) return;
foreach (var xmlAttr in from XmlNode xn in xmlNode select xn.Attributes)
{
if (xmlAttr == null) return;
for (var i = 0; i < xmlAttr.Count; i++)
{
if (xmlAttr.Item(i).Name != xmlNodeAttribute) continue;
xmlAttr.Item(i).Value = xmlNodeAttributeValue;
break;
}
}
}
catch (XmlException xmle)
{
throw new Exception(xmle.Message);
}
}
9.讀取XML文檔指定節點的值：
/// <summary>
/// 讀取XML資源中的指定節點內容
/// </summary>
/// <param name="source">XML資源</param>
/// <param name="xmlType">XML資源類型：文件，字符串</param>
/// <param name="nodeName">節點名稱</param>
/// <returns>節點內容</returns>
public static object GetNodeValue(string source, XmlType xmlType, string nodeName)
{
var xd = new XmlDocument();
if (xmlType == XmlType.File)
{
xd.Load(source);
}
else
{
xd.LoadXml(source);
}
var xe = xd.DocumentElement;
XmlNode xn = null;
if (xe != null)
{
xn= xe.SelectSingleNode("//" + nodeName);
}
return xn.InnerText;
}
10.更新XML文檔指定節點的內容：
/// <summary>
/// 更新XML文件中的指定節點內容
/// </summary>
/// <param name="filePath">文件路徑</param>
/// <param name="nodeName">節點名稱</param>
/// <param name="nodeValue">更新內容</param>
/// <returns>更新是否成功</returns>
public static bool UpdateNode(string filePath, string nodeName, string nodeValue)
{
try
{
bool flag;
var xd = new XmlDocument();
xd.Load(filePath);
var xe = xd.DocumentElement;
if (xe == null) return false;
var xn = xe.SelectSingleNode("//" + nodeName);
if (xn != null)
{
xn.InnerText = nodeValue;
flag = true;
}
else
{
flag = false;
}
return flag;
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
11.將對象轉化為XML文件，並存入指定目錄：
/// <summary>
/// 將對象轉化為xml，並寫入指定路徑的xml文件中
/// </summary>
/// <typeparam name="T">C#對象名</typeparam>
/// <param name="item">對象實例</param>
/// <param name="path">路徑</param>
/// <param name="jjdbh">標號</param>
/// <param name="ends">結束符號（整個xml的路徑類似如下：C:\xmltest\201111send.xml，其中path=C:\xmltest,jjdbh=201111,ends=send）</param>
/// <returns></returns>
public static string WriteXml<T>(T item, string path, string jjdbh, string ends)
{
if (string.IsNullOrEmpty(ends))
{
//默認為發送
ends = "send";
}
//控制寫入文件的次數
var i = 0;
//獲取當前對象的類型，也可以使用反射typeof(對象名)
var serializer = new XmlSerializer(item.GetType());
//xml的路徑組合
object[] obj = { path, "\\", jjdbh, ends, ".xml" };
var xmlPath = string.Concat(obj);
while (true)
{
try
{
//用filestream方式創建文件不會出現“文件正在占用中，用File.create”則不行
var fs = System.IO.File.Create(xmlPath);
fs.Close();
TextWriter writer = new StreamWriter(xmlPath, false, Encoding.UTF8);
var xml = new XmlSerializerNamespaces();
xml.Add(string.Empty, string.Empty);
serializer.Serialize(writer, item, xml);
writer.Flush();
writer.Close();
break;
}
catch (Exception)
{
if (i < 5)
{
i++;
continue;
}
break;
}
}
return SerializeToXmlStr<T>(item, true);
}
12.向一個已經存在的父節點中插入一個子節點：
/// <summary>
/// 向一個已經存在的父節點中插入一個子節點
/// </summary>
/// <param name="path"></param>
/// <param name="parentNodePath">父節點</param>
/// <param name="childnodename">子節點名稱</param>
public void AddChildNode(string path, string parentNodePath, string childnodename)
{
try
{
var xml = new XmlDocument();
xml.Load(path);
var parentXmlNode = xml.SelectSingleNode(parentNodePath);
XmlNode childXmlNode = xml.CreateElement(childnodename);
if ((parentXmlNode) != null)
{
//如果此節點存在
parentXmlNode.AppendChild(childXmlNode);
}
else
{
//如果不存在就放父節點添加
GetXmlRoot(path).AppendChild(childXmlNode);
}
}
catch (XmlException xmle)
{
throw new Exception(xmle.Message);
}
}
以上的方法總結采用.net4.5版本和c#6.0語法
