基于C#编写一个操作XML的简单类库XMLHelper
using System;
using System.Data;
using System.Xml;
namespace XMLHelper
{
class XMLHelper
{
private XmlDocument xmlDoc;
public XMLHelper()
{
xmlDoc = new XmlDocument();
}
// 从文件路径或字符串中加载XML文档，并返回XmlDocument对象
public XmlDocument LoadXmlDocumentFromFile(string filePath)
{
try
{
xmlDoc.Load(filePath);
return xmlDoc;
}
catch (Exception ex)
{
Console.WriteLine("Error loading XML document from file: " + ex.Message);
return null;
}
}
// 从一个XML字符串加载XML文档，并返回XmlDocument对象
public XmlDocument LoadXmlDocumentFromString(string xmlString)
{
try
{
xmlDoc.LoadXml(xmlString);
return xmlDoc;
}
catch (Exception ex)
{
Console.WriteLine("Error loading XML document from string: " + ex.Message);
return null;
}
}
// 保存XML文件：将XmlDocument对象保存为XML文件
public void SaveXmlDocument(XmlDocument xmlDoc, string filePath)
{
try
{
xmlDoc.Save(filePath);
}
catch (Exception ex)
{
Console.WriteLine("Error saving XML document: " + ex.Message);
}
}
// 生成一个新的XML文件，并指定根节点名称
public void GenerateXmlFile(string filePath, string rootElementName)
{
try
{
xmlDoc = new XmlDocument();
XmlDeclaration xmlDeclaration = xmlDoc.CreateXmlDeclaration("1.0", "UTF-8", null);
XmlNode rootNode = xmlDoc.CreateElement(rootElementName);
xmlDoc.AppendChild(xmlDeclaration);
xmlDoc.AppendChild(rootNode);
xmlDoc.Save(filePath);
}
catch (Exception ex)
{
Console.WriteLine("Error generating XML file: " + ex.Message);
}
}
///
/// 读取XML文件到DataTable：将XML文件中的数据读取到DataTable对象中
///
/// XmlDocument对象
/// 节点集合的 XPath 表达式 - 例如"/Roots/Child"
///
public DataTable ReadXmlToDataTable(XmlDocument xmlDoc,string xpath)
{
try
{
DataTable dataTable = new DataTable();
XmlNodeList nodes = xmlDoc.SelectNodes(xpath);
foreach (XmlNode node in nodes)
{
if (dataTable.Columns.Count == 0)
{
foreach (XmlNode childNode in node.ChildNodes)
{
dataTable.Columns.Add(childNode.Name, typeof(string));
}
}
DataRow row = dataTable.NewRow();
foreach (XmlNode childNode in node.ChildNodes)
{
row[childNode.Name] = childNode.InnerText;
}
dataTable.Rows.Add(row);
}
return dataTable;
}
catch (Exception ex)
{
Console.WriteLine("Error reading XML document to DataTable: " + ex.Message);
return null;
}
}
///
/// 将DataTable对象中的数据更新到XML文件中
///
/// XmlDocument对象
/// DataTable对象
/// 子节点值
public void UpdateXmlFromDataTable(XmlDocument xmlDoc, DataTable dataTable,string elementName)
{
try
{
xmlDoc.DocumentElement.RemoveAll();
foreach (DataRow row in dataTable.Rows)
{
XmlElement measurementPointElement = xmlDoc.CreateElement(elementName);
foreach (DataColumn column in dataTable.Columns)
{
XmlElement element = xmlDoc.CreateElement(column.ColumnName);
element.InnerText = row[column.ColumnName].ToString();
measurementPointElement.AppendChild(element);
}
xmlDoc.DocumentElement.AppendChild(measurementPointElement);
}
}
catch (Exception ex)
{
Console.WriteLine("Error updating XML from DataTable: " + ex.Message);
}
}
// 根据XPath表达式获取指定节点的值
public string GetNodeValue(XmlDocument xmlDoc, string xpath)
{
XmlNode node = xmlDoc.SelectSingleNode(xpath);
return node?.InnerText;
}
// 根据XPath表达式设置指定节点的值
public void SetNodeValue(XmlDocument xmlDoc, string xpath, string value)
{
XmlNode node = xmlDoc.SelectSingleNode(xpath);
if (node != null)
node.InnerText = value;
}
// 根据XPath表达式和属性名称获取指定节点的属性值
public string GetAttributeValue(XmlDocument xmlDoc, string xpath, string attributeName)
{
XmlNode node = xmlDoc.SelectSingleNode(xpath);
if (node != null && node.Attributes != null)
{
XmlAttribute attribute = node.Attributes[attributeName];
return attribute?.Value;
}
return null;
}
// 根据XPath表达式和属性名称设置指定节点的属性值
public void SetAttributeValue(XmlDocument xmlDoc, string xpath, string attributeName, string value)
{
XmlNode node = xmlDoc.SelectSingleNode(xpath);
if (node != null && node.Attributes != null)
{
XmlAttribute attribute = node.Attributes[attributeName];
if (attribute != null)
attribute.Value = value;
}
}
// 根据文件路径、XPath表达式和值更新XML文件中的节点值
public void UpdateNodeValueInFile(string filePath, string xpath, string value)
{
XmlDocument doc = LoadXmlDocumentFromFile(filePath);
if (doc != null)
{
SetNodeValue(doc, xpath, value);
SaveXmlDocument(doc, filePath);
}
}
// 根据文件路径、XPath表达式、属性名称和值更新XML文件中的属性值
public void UpdateAttributeValueInFile(string filePath, string xpath, string attributeName, string value)
{
XmlDocument doc = LoadXmlDocumentFromFile(filePath);
if (doc != null)
{
SetAttributeValue(doc, xpath, attributeName, value);
SaveXmlDocument(doc, filePath);
}
}
}
}