引言:在实际项目中遇到一些关于xml操作的问题,被逼到无路可退的时候终于决定好好研究xml一番。本文首先介绍了xml的基本操作,后面写了一个经常用到的xml保存配置文件的实例。
xml常用方法:
定义xml文档:XmlDocument xmlDoc = new XmlDocument();
初始化xml文档:xmlDoc.Load("D:\\book.xml");//找到xml文件
创建根元素:XmlElement xmlElement = xmlDoc.CreateElement("","Employees","");
创建节点:XmlElement xeSub1 = xmlDoc.CreateElement("title");
查找Employees节点:XmlNode root = xmlDoc.SelectSingleNode("Employees");
添加节点:xe1.AppendChild(xeSub1);
更改节点的属性:xe.SetAttribute("Name","李明明");
移除xe的ID属性:xe.RemoveAttribute("ID");
删除节点title:xe.RemoveChild(xe2);
1 创建xml文档
因为比较简单,直接写方法及结果。
public void CreateXMLDocument()
{
XmlDocument xmlDoc = new XmlDocument();
//加入XML的声明段落,<?xml version="1.0" encoding="gb2312"?>
XmlDeclaration xmlDeclar;
xmlDeclar = xmlDoc.CreateXmlDeclaration("1.0","gb2312",null);
xmlDoc.AppendChild(xmlDeclar);
//加入Employees根元素
XmlElement xmlElement = xmlDoc.CreateElement("","");
xmlDoc.AppendChild(xmlElement);
//添加节点
XmlNode root = xmlDoc.SelectSingleNode("Employees");
XmlElement xe1 = xmlDoc.CreateElement("Node");
xe1.SetAttribute("Name","李明");
xe1.SetAttribute("ISB","2-3631-4");
//添加子节点
XmlElement xeSub1 = xmlDoc.CreateElement("title");
xeSub1.InnerText = "学习VS";
xe1.AppendChild(xeSub1);
XmlElement xeSub2 = xmlDoc.CreateElement("price");
xe1.AppendChild(xeSub2);
XmlElement xeSub3 = xmlDoc.CreateElement("weight");
xeSub3.InnerText = "20";
xeSub2.AppendChild(xeSub3);
root.AppendChild(xe1);
xmlDoc.Save("D:\\book.xml");//保存的路径
}
结果:
<?xml version="1.0" encoding="GB2312"?>
-<Employees>-
<Node ISB="2-3631-4" Name="李明">
<title>学习VS</title>-
<price>
<weight>20</weight>
</price>
</Node>
</Employees>
2 增加节点
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("D:\\book.xml");//找到xml文件
XmlNode root = xmlDoc.SelectSingleNode("Employees");//查找Employees节点
XmlElement xe1 = xmlDoc.CreateElement("Node2");//添加Node2节点
xe1.SetAttribute("Name","张三");
XmlElement xeSub1 = xmlDoc.CreateElement("title");//定义子节点
xeSub1.InnerText = "心情好";
xe1.AppendChild(xeSub1);//添加节点到Node2
root.AppendChild(xe1);//添加节点到Employees
xmlDoc.Save("D:\\book.xml");
结果:
<?xml version="1.0" encoding="GB2312"?>
-<Employees>
-<Node ISB="2-3631-4" Name="李明">
<title>学习VS</title>-
<price>
<weight>20</weight>
</price>
</Node>-
<Node2 Name="张三">
<title>心情好</title>
</Node2>-
<Node2 Name="张三">
<title>心情好</title>
</Node2>
</Employees>
3 修改节点:
public void ModifyNode() { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load("D:\\book.xml"); XmlNodeList nodeList = xmlDocument.SelectSingleNode("Employees").ChildNodes;//获取Employees节点的所有子节点 foreach (XmlNode xn in nodeList)//遍历 { XmlElement xe = (XmlElement)xn; if (xe.GetAttribute("Name") == "李明") { xe.SetAttribute("Name","李明明");//更改节点的属性 XmlNodeList xnl = xe.ChildNodes;//获取xe的所有子节点 foreach (XmlNode xn1 in xnl) { XmlElement xe2 = (XmlElement)xn1;//将节点xn1的属性转换为XmlElement if (xe2.Name == "title")//找到节点名字为title的节点 { xe2.InnerText = "今天天气不好"; } if (xe2.Name == "price") { XmlNodeList xnl2 = xe2.ChildNodes; foreach (XmlNode xn2 in xnl2) { if (xn2.Name == "weight") { xn2.InnerText = "88"; } } } } } } xmlDocument.Save("D:\\book2.xml"); } result: <?xml version="1.0" encoding="GB2312"?> -<Employees> -<Node ISB="2-3631-4" Name="李明明"> <title>今天天气不好</title>-<price> <weight>88</weight> </price> </Node> -<Node2 Name="张三"> <title>心情好</title> </Node2></Employees>
4 删除节点:
public void DeleteNode() { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load("D:\\book1.xml"); XmlNodeList xnl = xmlDocument.SelectSingleNode("Employees").ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == "Node") { XmlElement xe = (XmlElement)xn;//将xn的属性转换为XmlElement xe.RemoveAttribute("ID");//移除xe的ID属性 XmlNodeList xnl2 = xe.ChildNodes; for (int i = 0; i < xnl2.Count; i++) { XmlElement xe2 = (XmlElement)xnl2.Item(i); if (xe2.Name == "title") { xe.RemoveChild(xe2);//删除节点title } } } } xmlDocument.Save("D:\\book3.xml"); } 结果: <?xml version="1.0" encoding="GB2312"?> -<Employees> -<Node ISB="2-3631-4" Name="李明">-<price> <weight>20</weight> </price> </Node>- <Node2 Name="张三"> <title>心情好</title> </Node2>- <Node2 Name="张三"> <title>心情好</title> </Node2> </Employees>
前面介绍了xml的创建、节点的添加、节点的修改和删除,下面以写的一个保存项目配置文件的小例子。
举例说明:
首先在项目文件中创建一个xml文档:
<?xml version="1.0" encoding="utf-8" ?>
<configurationN>
<ServerAddress>1143</ServerAddress>
<ID>192.168</ID>
</configurationN>
在保存配置文件时,最主要使用了两个方法:Load和Save。
Load:初始化xml文档,以便项目文件获取具体的xml节点的值。
public void Load(string path) { try { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load(path); XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == configuration_ServerAddress) { ServerAddress = xn.InnerText; } } } catch(Exception ex) { } }
Save:在项目系统中进行修改配置文件值后,需要对xml进行重新保存
public void Save(string path) { try { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load(path); XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == configuration_ServerAddress) { xn.InnerText = ServerAddress; } } xmlDocument.Save(path); } catch (Exception ex) { } }
此处将所有代码都贴出来,方便下次实现。因为项目是WPF文件,而且都是简单控件,所以只贴出后台代码。
class ConfigurationManager:INotifyPropertyChanged { public const string managerNode = "configurationN";//根节点 public const string configuration_ServerAddress = "ServerAddress";//子节点 private string _ServerAddress; public string ServerAddress { get { return _ServerAddress; } set { _ServerAddress = value; NotifyPropertyChanged("ServerAddress"); } } public void Load(string path) { try { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load(path); XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == configuration_ServerAddress) { ServerAddress = xn.InnerText; } } } catch(Exception ex) { } } public void Save(string path) { try { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load(path); XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == configuration_ServerAddress) { xn.InnerText = ServerAddress; } } xmlDocument.Save(path); } catch (Exception ex) { } } public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this,new PropertyChangedEventArgs(propertyName)); } } public static ConfigurationManager Instance = new ConfigurationManager(); } public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); Start(); this.tb1.Text = ConfigurationManager.Instance.ServerAddress.ToString(); } private string path = "CONFIG\\System.xml"; private void button1_Click(object sender,RoutedEventArgs e) { ConfigurationManager.Instance.ServerAddress = this.tb1.Text; ConfigurationManager.Instance.Save(path); } private void button2_Click(object sender,RoutedEventArgs e) { Application.Current.Shutdown(); } private void Start() { ConfigurationManager.Instance.Load(path); } }