(精华)2020年8月12日 C#基础知识点 XML文件相关操作
/// <summary>
/// Linq to xml示例
/// </summary>
public class LinqToXml
{<!-- -->
/// <summary>
/// 创建XML文件
/// </summary>
/// <param name="xmlPath"></param>
private static void CreateXmlFile(string xmlPath)
{<!-- -->
try
{<!-- -->
//定义一个XDocument结构
XDocument myXDoc = new XDocument(
new XElement("Users",
new XElement("User", new XAttribute("ID", "111111"),
new XElement("name", "EricSun"),
new XElement("password", "123456"),
new XElement("description", "Hello I'm from Dalian")),
new XElement("User", new XAttribute("ID", "222222"),
new XElement("name", "Ray"),
new XElement("password", "654321"),
new XElement("description", "Hello I'm from Jilin"))));
//保存此结构（即：我们预期的xml文件）
myXDoc.Save(xmlPath);
string aa = myXDoc.ToString();
}
catch (Exception ex)
{<!-- -->
Console.WriteLine(ex.ToString());
}
}
/// <summary>
/// 遍历xml信息
/// </summary>
/// <param name="xmlPath"></param>
private static void GetXmlNodeInformation(string xmlPath)
{<!-- -->
try
{<!-- -->
//定义并从xml文件中加载节点（根节点）
XElement rootNode = XElement.Load(xmlPath);
//XElement rootNode2 = XElement.Parse(xmlPath);
//查询语句: 获得根节点下name子节点（此时的子节点可以跨层次：孙节点、重孙节点......）
IEnumerable<XElement> targetNodes = from target in rootNode.Descendants("name")
select target;
foreach (XElement node in targetNodes)
{<!-- -->
Console.WriteLine("name = {0}", node.Value);
}
//查询语句: 获取ID属性值等于"111111"并且函数子节点的所有User节点（并列条件用"&&"符号连接）
IEnumerable<XElement> myTargetNodes = from myTarget in rootNode.Descendants("User")
where myTarget.Attribute("ID").Value.Equals("111111")
&& myTarget.HasElements
select myTarget;
foreach (XElement node in myTargetNodes)
{<!-- -->
Console.WriteLine("name = {0}", node.Element("name").Value);
Console.WriteLine("password = {0}", node.Element("password").Value);
Console.WriteLine("description = {0}", node.Element("description").Value);
}
}
catch (Exception ex)
{<!-- -->
Console.WriteLine(ex.ToString());
}
}
/// <summary>
/// 修改xml信息
/// </summary>
/// <param name="xmlPath"></param>
public static void ModifyXmlNodeInformation(string xmlPath)
{<!-- -->
try
{<!-- -->
//定义并从xml文件中加载节点（根节点）
XElement rootNode = XElement.Load(xmlPath);
//查询语句: 获取ID属性值等于"222222"或者等于"777777"的所有User节点（或条件用"||"符号连接）
IEnumerable<XElement> targetNodes = from target in rootNode.Descendants("User")
where target.Attribute("ID").Value == "222222"
|| target.Attribute("ID").Value.Equals("777777")
select target;
//遍历所获得的目标节点（集合）
foreach (XElement node in targetNodes)
{<!-- -->
//将description节点的InnerText设置为"Hello, I'm from USA."
node.Element("description").SetValue("Hello, I'm from USA.");
}
//保存对xml的更改操作
rootNode.Save(xmlPath);
}
catch (Exception ex)
{<!-- -->
Console.WriteLine(ex.ToString());
}
}
/// <summary>
/// 添加xml信息
/// </summary>
/// <param name="xmlPath"></param>
private static void AddXmlNodeInformation(string xmlPath)
{<!-- -->
try
{<!-- -->
//定义并从xml文件中加载节点（根节点）
XElement rootNode = XElement.Load(xmlPath);
//定义一个新节点
XElement newNode = new XElement("User", new XAttribute("ID", "999999"),
new XElement("name", "Rose"),
new XElement("password", "456123"),
new XElement("description", "Hello, I'm from UK."));
//将此新节点添加到根节点下
rootNode.Add(newNode);
//Add 在 XContainer 的子内容的末尾添加内容。
//AddFirst 在 XContainer 的子内容的开头添加内容。
//AddAfterSelf 在 XNode 后面添加内容。
//AddBeforeSelf 在 XNode 前面添加内容。
//保存对xml的更改操作
rootNode.Save(xmlPath);
}
catch (Exception ex)
{<!-- -->
Console.WriteLine(ex.ToString());
}
}
/// <summary>
/// 删除xml信息
/// </summary>
/// <param name="xmlPath"></param>
private static void DeleteXmlNodeInformation(string xmlPath)
{<!-- -->
try
{<!-- -->
//定义并从xml文件中加载节点（根节点）
XElement rootNode = XElement.Load(xmlPath);
//查询语句: 获取ID属性值等于"999999"的所有User节点
IEnumerable<XElement> targetNodes = from target in rootNode.Descendants("User")
where target.Attribute("ID").Value.Equals("999999")
select target;
//将获得的节点集合中的每一个节点依次从它相应的父节点中删除
targetNodes.Remove();
//保存对xml的更改操作
rootNode.Save(xmlPath);
}
catch (Exception ex)
{<!-- -->
Console.WriteLine(ex.ToString());
}
}
}
public static class xHelper
{<!-- -->
/// <summary>
/// 实体转化为XML
/// </summary>
public static string ParseToXml<T>(this T model, string fatherNodeName)
{<!-- -->
var xmldoc = new XmlDocument();
var modelNode = xmldoc.CreateElement(fatherNodeName);
xmldoc.AppendChild(modelNode);
if (model != null)
{<!-- -->
foreach (PropertyInfo property in model.GetType().GetProperties())
{<!-- -->
var attribute = xmldoc.CreateElement(property.Name);
if (property.GetValue(model, null) != null)
attribute.InnerText = property.GetValue(model, null).ToString();
//else
// attribute.InnerText = "[Null]";
modelNode.AppendChild(attribute);
}
}
return xmldoc.OuterXml;
}
/// <summary>
/// XML转换为实体,默认 fatherNodeName="body"
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="xml"></param>
/// <param name="fatherNodeName"></param>
/// <returns></returns>
public static T ParseToModel<T>(this string xml, string fatherNodeName = "body") where T : class ,new()
{<!-- -->
if (string.IsNullOrEmpty(xml))
return default(T);
var xmldoc = new XmlDocument();
xmldoc.LoadXml(xml);
T model = new T();
var attributes = xmldoc.SelectSingleNode(fatherNodeName).ChildNodes;
foreach (XmlNode node in attributes)
{<!-- -->
foreach (var property in model.GetType().GetProperties().Where(property => node.Name == property.Name))
{<!-- -->
if (!string.IsNullOrEmpty(node.InnerText))
{<!-- -->
property.SetValue(model,
property.PropertyType == typeof(Guid)
? new Guid(node.InnerText)
: Convert.ChangeType(node.InnerText, property.PropertyType));
}
else
{<!-- -->
property.SetValue(model, null);
}
}
}
return model;
}
/// <summary>
/// XML转实体
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="xml"></param>
/// <param name="headtag"></param>
/// <returns></returns>
public static List<T> XmlToObjList<T>(this string xml, string headtag)
where T : new()
{<!-- -->
var list = new List<T>();
XmlDocument doc = new XmlDocument();
PropertyInfo[] propinfos = null;
doc.LoadXml(xml);
XmlNodeList nodelist = doc.SelectNodes(headtag);
foreach (XmlNode node in nodelist)
{<!-- -->
T entity = new T();
if (propinfos == null)
{<!-- -->
Type objtype = entity.GetType();
propinfos = objtype.GetProperties();
}
foreach (PropertyInfo propinfo in propinfos)
{<!-- -->
//实体类字段首字母变成小写的
string name = propinfo.Name.Substring(0, 1) + propinfo.Name.Substring(1, propinfo.Name.Length - 1);
XmlNode cnode = node.SelectSingleNode(name);
string v = cnode.InnerText;
if (v != null)
propinfo.SetValue(entity, Convert.ChangeType(v, propinfo.PropertyType), null);
}
list.Add(entity);
}
return list;
}
}
