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Comment changer l'attribut XML

Comment puis-je changer l'attribut d'un élément dans un fichier XML en utilisant C #?

c#xmllinq-to-xmlxmldocument
58
Mike

Mike; À chaque fois que je dois modifier un document XML, je le travaille de cette façon:

//Here is the variable with which you assign a new value to the attribute
string newValue = string.Empty;
XmlDocument xmlDoc = new XmlDocument();

xmlDoc.Load(xmlFile);

XmlNode node = xmlDoc.SelectSingleNode("Root/Node/Element");
node.Attributes[0].Value = newValue;

xmlDoc.Save(xmlFile);

//xmlFile is the path of your file to be modified

J'espère que tu trouves cela utile

64
El Padrino

Utilisation de LINQ en XML si vous utilisez Framework 3.5:

using System.Xml.Linq;

XDocument xmlFile = XDocument.Load("books.xml"); 

var query = from c in xmlFile.Elements("catalog").Elements("book")    
            select c; 

foreach (XElement book in query) 
{
   book.Attribute("attr1").Value = "MyNewValue";
}

xmlFile.Save("books.xml");
59
alexmac

Si l'attribut que vous souhaitez modifier n'existe pas ou a été supprimé accidentellement, une exception se produit. Je vous suggère tout d'abord de créer un nouvel attribut et de l'envoyer à une fonction comme celle-ci:

private void SetAttrSafe(XmlNode node,params XmlAttribute[] attrList)
    {
        foreach (var attr in attrList)
        {
            if (node.Attributes[attr.Name] != null)
            {
                node.Attributes[attr.Name].Value = attr.Value;
            }
            else
            {
                node.Attributes.Append(attr);
            }
        }
    }

Usage:

   XmlAttribute attr = dom.CreateAttribute("name");
   attr.Value = value;
   SetAttrSafe(node, attr);
12
Ahmad

Voici le début d’une classe d’analyseur pour vous aider à démarrer. Cela a fini par être ma solution à un problème similaire:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Linq;

namespace XML
{
    public class Parser
    {

        private string _FilePath = string.Empty;

        private XDocument _XML_Doc = null;


        public Parser(string filePath)
        {
            _FilePath = filePath;
            _XML_Doc = XDocument.Load(_FilePath);
        }


        /// <summary>
        /// Replaces values of all attributes of a given name (attributeName) with the specified new value (newValue) in all elements.
        /// </summary>
        /// <param name="attributeName"></param>
        /// <param name="newValue"></param>
        public void ReplaceAtrribute(string attributeName, string newValue)
        {
            ReplaceAtrribute(string.Empty, attributeName, new List<string> { }, newValue);
        }

        /// <summary>
        /// Replaces values of all attributes of a given name (attributeName) with the specified new value (newValue) in elements with a given name (elementName).
        /// </summary>
        /// <param name="elementName"></param>
        /// <param name="attributeName"></param>
        /// <param name="newValue"></param>
        public void ReplaceAtrribute(string elementName, string attributeName, string newValue)
        {
            ReplaceAtrribute(elementName, attributeName, new List<string> { }, newValue);
        }


        /// <summary>
        /// Replaces values of all attributes of a given name (attributeName) and value (oldValue)  
        /// with the specified new value (newValue) in elements with a given name (elementName).
        /// </summary>
        /// <param name="elementName"></param>
        /// <param name="attributeName"></param>
        /// <param name="oldValue"></param>
        /// <param name="newValue"></param>
        public void ReplaceAtrribute(string elementName, string attributeName, string oldValue, string newValue)
        {
            ReplaceAtrribute(elementName, attributeName, new List<string> { oldValue }, newValue);              
        }


        /// <summary>
        /// Replaces values of all attributes of a given name (attributeName), which has one of a list of values (oldValues), 
        /// with the specified new value (newValue) in elements with a given name (elementName).
        /// If oldValues is empty then oldValues will be ignored.
        /// </summary>
        /// <param name="elementName"></param>
        /// <param name="attributeName"></param>
        /// <param name="oldValues"></param>
        /// <param name="newValue"></param>
        public void ReplaceAtrribute(string elementName, string attributeName, List<string> oldValues, string newValue)
        {
            List<XElement> elements = _XML_Doc.Elements().Descendants().ToList();

            foreach (XElement element in elements)
            {
                if (elementName == string.Empty | element.Name.LocalName.ToString() == elementName)
                {
                    if (element.Attribute(attributeName) != null)
                    {

                        if (oldValues.Count == 0 || oldValues.Contains(element.Attribute(attributeName).Value))
                        { element.Attribute(attributeName).Value = newValue; }
                    }
                }
            }

        }

        public void SaveChangesToFile()
        {
            _XML_Doc.Save(_FilePath);
        }

    }
}
0
Edward Bagby