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("", "Employees", "");
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 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>
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);
}
}
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);
}
}