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 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);
        }
    }