C # Summary of XML operation methods,

C # Summary of XML operation methods,

Using System. Xml;
Using System. Data;

Namespace DotNet. Utilities
{
/// <Summary>
/// Common Xml operation class
/// </Summary>
Public class XmlHelper
{
# Region field Definition
/// <Summary>
/// Physical path of the XML file
/// </Summary>
Private string _ filePath = string. Empty;
/// <Summary>
/// Xml document
/// </Summary>
Private XmlDocument _ xml;
/// <Summary>
/// XML Root Node
/// </Summary>
Private XmlElement _ element;
# Endregion

# Region Constructor
/// <Summary>
/// Instantiate the XmlHelper object
/// </Summary>
/// <Param name = "xmlFilePath"> relative path of the Xml file </param>
Public XmlHelper (string xmlFilePath)
{
// Obtain the absolute path of the XML file
_ FilePath = SysHelper. GetPath (xmlFilePath );
}
# Endregion

# Region create the XML Root Node
/// <Summary>
/// Create the XML Root Node
/// </Summary>
Private void CreateXMLElement ()
{

// Create an XML Object
_ Xml = new XmlDocument ();

If (DirFile. IsExistFile (_ filePath ))
{
// Load the XML file
_ Xml. Load (this. _ filePath );
}

// Assign values to the XML Root Node
_ Element = _ xml. DocumentElement;
}
# Endregion

# Region get the Node object of the specified XPath expression
/// <Summary>
/// Obtain the Node object of the specified XPath expression
/// </Summary>
/// <Param name = "xPath"> XPath expression,
/// Example 1: @ "Skill/First/SkillItem", equivalent to @ "// Skill/First/SkillItem"
/// Example 2: @ "Table [USERNAME = 'a']", [] indicates filtering. USERNAME is a subnode in Table.
/// Example 3: @ "ApplyPost/Item [@ itemName = 'Post number']", @ itemName is the attribute of the Item node.
/// </Param>
Public XmlNode GetNode (string xPath)
{
// Create the XML Root Node
CreateXMLElement ();

// Return the XPath Node
Return _ element. SelectSingleNode (xPath );
}
# Endregion

# Region obtain the node value of the specified XPath expression
/// <Summary>
/// Obtain the node value of the specified XPath expression
/// </Summary>
/// <Param name = "xPath"> XPath expression,
/// Example 1: @ "Skill/First/SkillItem", equivalent to @ "// Skill/First/SkillItem"
/// Example 2: @ "Table [USERNAME = 'a']", [] indicates filtering. USERNAME is a subnode in Table.
/// Example 3: @ "ApplyPost/Item [@ itemName = 'Post number']", @ itemName is the attribute of the Item node.
/// </Param>
Public string GetValue (string xPath)
{
// Create the XML Root Node
CreateXMLElement ();

// Return the value of the XPath Node
Return _ element. SelectSingleNode (xPath). InnerText;
}
# Endregion

# Region get the attribute value of the node of the specified XPath expression
/// <Summary>
/// Obtain the attribute value of the node of the specified XPath expression
/// </Summary>
/// <Param name = "xPath"> XPath expression,
/// Example 1: @ "Skill/First/SkillItem", equivalent to @ "// Skill/First/SkillItem"
/// Example 2: @ "Table [USERNAME = 'a']", [] indicates filtering. USERNAME is a subnode in Table.
/// Example 3: @ "ApplyPost/Item [@ itemName = 'Post number']", @ itemName is the attribute of the Item node.
/// </Param>
/// <Param name = "attributeName"> attribute name </param>
Public string GetAttributeValue (string xPath, string attributeName)
{
// Create the XML Root Node
CreateXMLElement ();

// Return the attribute value of the XPath Node
Return _ element. SelectSingleNode (xPath). Attributes [attributeName]. Value;
}
# Endregion

# Add a node to region
/// <Summary>
/// 1. function: Add a node.
/// 2. usage condition: insert any node into the current Xml file.
/// </Summary>
/// <Param name = "xmlNode"> Xml node to be inserted </param>
Public void AppendNode (XmlNode xmlNode)
{
// Create the XML Root Node
CreateXMLElement ();

// Import nodes
XmlNode node = _ xml. ImportNode (xmlNode, true );

// Insert the node to the root node
_ Element. AppendChild (node );
}

/// <Summary>
/// 1. function: Add a node.
/// 2. usage condition: insert the first record in DataSet into the Xml file.
/// </Summary>
/// <Param name = "ds"> DataSet instance, This DataSet should have only one record </param>
Public void AppendNode (DataSet ds)
{
// Create an XmlDataDocument object
XmlDataDocument xmlDataDocument = new XmlDataDocument (ds );

// Import nodes
XmlNode node = xmlDataDocument. DocumentElement. FirstChild;

// Insert the node to the root node
AppendNode (node );
}
# Endregion

# Region delete a node
/// <Summary>
/// Delete the node of the specified XPath expression
/// </Summary>
/// <Param name = "xPath"> XPath expression,
/// Example 1: @ "Skill/First/SkillItem", equivalent to @ "// Skill/First/SkillItem"
/// Example 2: @ "Table [USERNAME = 'a']", [] indicates filtering. USERNAME is a subnode in Table.
/// Example 3: @ "ApplyPost/Item [@ itemName = 'Post number']", @ itemName is the attribute of the Item node.
/// </Param>
Public void RemoveNode (string xPath)
{
// Create the XML Root Node
CreateXMLElement ();

// Obtain the node to be deleted
XmlNode node = _ xml. SelectSingleNode (xPath );

// Delete a node
_ Element. RemoveChild (node );
}
# Endregion // delete a node

# Region saving XML files
/// <Summary>
/// Save the XML file
/// </Summary>
Public void Save ()
{
// Create the XML Root Node
CreateXMLElement ();

// Save the XML file
_ Xml. Save (this. _ filePath );
}
# Endregion // Save the XML file

# Region static method

# Region create a Root Node object
/// <Summary>
/// Create a Root Node object
/// </Summary>
/// <Param name = "xmlFilePath"> relative path of the Xml file </param>
Private static XmlElement CreateRootElement (string xmlFilePath)
{
// Define the variable, indicating the absolute path of the XML file
String filePath = "";

// Obtain the absolute path of the XML file
FilePath = SysHelper. GetPath (xmlFilePath );

// Create an XmlDocument object
XmlDocument xmlDocument = new XmlDocument ();
// Load the XML file
XmlDocument. Load (filePath );

// Return the root node
Return xmlDocument. DocumentElement;
}
# Endregion

# Region obtain the node value of the specified XPath expression
/// <Summary>
/// Obtain the node value of the specified XPath expression
/// </Summary>
/// <Param name = "xmlFilePath"> relative path of the Xml file </param>
/// <Param name = "xPath"> XPath expression,
/// Example 1: @ "Skill/First/SkillItem", equivalent to @ "// Skill/First/SkillItem"
/// Example 2: @ "Table [USERNAME = 'a']", [] indicates filtering. USERNAME is a subnode in Table.
/// Example 3: @ "ApplyPost/Item [@ itemName = 'Post number']", @ itemName is the attribute of the Item node.
/// </Param>
Public static string GetValue (string xmlFilePath, string xPath)
{
// Create the root object
XmlElement rootElement = CreateRootElement (xmlFilePath );

// Return the value of the XPath Node
Return rootElement. SelectSingleNode (xPath). InnerText;
}
# Endregion

# Region get the attribute value of the node of the specified XPath expression
/// <Summary>
/// Obtain the attribute value of the node of the specified XPath expression
/// </Summary>
/// <Param name = "xmlFilePath"> relative path of the Xml file </param>
/// <Param name = "xPath"> XPath expression,
/// Example 1: @ "Skill/First/SkillItem", equivalent to @ "// Skill/First/SkillItem"
/// Example 2: @ "Table [USERNAME = 'a']", [] indicates filtering. USERNAME is a subnode in Table.
/// Example 3: @ "ApplyPost/Item [@ itemName = 'Post number']", @ itemName is the attribute of the Item node.
/// </Param>
/// <Param name = "attributeName"> attribute name </param>
Public static string GetAttributeValue (string xmlFilePath, string xPath, string attributeName)
{
// Create the root object
XmlElement rootElement = CreateRootElement (xmlFilePath );

// Return the attribute value of the XPath Node
Return rootElement. SelectSingleNode (xPath). Attributes [attributeName]. Value;
}
# Endregion

# Endregion

Public static void SetValue (string xmlFilePath, string xPath, string newtext)
{
// String path = SysHelper. GetPath (xmlFilePath );
// Var queryXML = from xmlLog in xelem. Descendants ("msg_log ")
/// All records whose names are Bin
// Where xmlLog. Element ("user"). Value = "Bin"
// Select xmlLog;

// Foreach (XElement el in queryXML)
//{
// El. Element ("user"). Value = "LiuBin"; // start modification
//}
// Xelem. Save (path );
}
}
}