xml基本操作和保存配置文件应用实例

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 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);
}
}