C operates the XML file instance summary

  • 2020-08-22 22:38:18
  • OfStack

Working with XML files is a very common feature in C# programming. This article demonstrates a few common examples of C# working with XML files. The details are as follows:

1. Return node index


public static XmlDocument getDoc(String path)// loading xml The document 
{
  XmlDocument doc = new XmlDocument();
  doc.Load(path);
  return doc;
} 
/// <summary>
///  Returns the index of the node found 
/// </summary>
/// <param name="path">xml The file path </param>
/// <param name="bname"> Title: </param>
/// <returns></returns>
public static int getPosition(String path,string node, String bname)
{
  int i;
  XmlDocument doc = new XmlDocument();
  doc.Load(path);
  XmlNodeList nodeList = doc.SelectSingleNode(node).ChildNodes;
  for (i = 0; i < nodeList.Count; i++)
  {
 if (nodeList[i].ChildNodes[0].InnerText == bname)
 {
   return i;
 }
  }
  return -1;
}

2. Traverse the data


/// <summary>
///  Through the data 
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btnRead_Click(object sender, EventArgs e)
{

  XmlDocument doc = getDoc("books.xml");// loading xml The document, books File in 
  foreach (XmlElement root in doc.DocumentElement.ChildNodes)// Iterate over the child nodes of the root 
  {
 Response.Write("<script>document.write('<br/>');</script>");
 Response.Write("<script>document.write('" + root.Name + "');</script>");// The node name root.Name book
 foreach (XmlElement item in root.ChildNodes)
 {
   Response.Write("<script>document.write('" + item.Name + "'+':'+'" + item.InnerText + "');</script>");// Outputs the node name and the value of the text node 
   Response.Write("<script>document.write('<br/>');</script>");
 }
  }
}

3. Look for


/// <summary>
///  To find the 
/// </summary>
/// <param name="path"> The file path </param>
/// <param name="node"> node </param>
/// <param name="bname"> Find keywords </param>
/// <returns>XmlNode</returns>
public static XmlNode Find(string path,string node,string bname)
{
  XmlDocument doc = new XmlDocument();
  doc.Load(path);// loading xml The document 
  XmlNodeList nodeList = doc.SelectSingleNode(node).ChildNodes;
  int i = getPosition(path, node, bname);//
  if (i >= 0)
 return nodeList[i];
  else
 return null;
}

4. Delete nodes


/// <summary>
///  Deletes elements, attributes 
/// </summary>
/// <param name="path"> file </param>
/// <param name="node"> Specifies the parent node of the node </param>
/// <param name="attribute"> Deletes the node when null, or deletes the property </param>
/// <param name="bname"></param>
public static void Delete(string path,string node,string attribute,string bname)
{
  XmlDocument doc = new XmlDocument();
  doc.Load(path);
  XmlNode root = doc.SelectSingleNode(node);
  XmlNodeList nodeList = doc.SelectSingleNode(node).ChildNodes;
  int i = getPosition(path, node, bname);// Returns the specified node index 
  if (i >= 0)
  {
 if (attribute.Equals(""))
 {
   root.RemoveChild(nodeList[i]);
 }
 else
 {
   XmlElement xn = (XmlElement)nodeList[i];
   xn.RemoveAttribute(attribute);
 }
  }
  doc.Save(path);
}

5. Add


/// <summary>
///  Add element values 
/// </summary>
/// <param name="path"></param>
/// <param name="node"></param>
/// <param name="element"></param>
/// <param name="value"></param>
/// <param name="i"> Insert subscript, if negative, default from last 1 Node insertion </param>
/// <returns></returns>
public static bool Add(string path,string node,string element,string value,int i)
{
  XmlDocument doc = new XmlDocument();
  doc.Load(path);
  XmlNodeList nodeList = doc.SelectNodes(node);
  XmlNode newNode = doc.SelectSingleNode(node).LastChild;
  if (i < 0 || i > nodeList.Count-1)// If less than 0 Or greater than the node length, default from last 1 Node addition 
  {
 XmlElement newElement = doc.CreateElement(element);// Create the element 
 newElement.InnerText = value;// The assignment 
 newNode.AppendChild(newElement);
  }
  else
  {
 XmlElement newElement = doc.CreateElement(element);
 newElement.InnerText = value;
 nodeList[i - 1].AppendChild(newElement);
  }
  doc.Save(path);
  return true;
}

Hopefully, the approach described in this article has helped you with your C# programming.


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