CODEWITHSUNDEEP
c#xml
user2962759
user2962759

Reputation: 59

Auto increment ID value in xml file

I want to add a new node to my xml file, but also, i would like to add id value in it, but incremented by 1 from the last value. Here is my XML:

  <users>
      <user>
        <id>1</id>
        <name>Name1</name>
        <surname>Surname1</surname>
        <weight>78</weight>
        <height>180</height>
      </user>
      <user>
        <id>2</id>
        <name>Name2</name>
        <surname>Surname2</surname>
        <weight>84</weight>
        <height>180</height>
      </user>
    </users>

And here is my code so far (for adding a new node):

        XmlNode node = xmlDoc.SelectSingleNode("/users/user");
        XmlNode newNode = xmlDoc.ImportNode(node, true);
        xmlDoc.DocumentElement.AppendChild(newNode);

        xmlDoc.SelectSingleNode("users/user/id").InnerText = ; // <-- ??
        xmlDoc.SelectSingleNode("users/user/name").InnerText = nameBox.Text;
        xmlDoc.SelectSingleNode("users/user/surname").InnerText = surnameBox.Text;
        xmlDoc.SelectSingleNode("users/user/weight").InnerText = Convert.ToString(weightUpDown.Value);
        xmlDoc.SelectSingleNode("users/user/height").InnerText = Convert.ToString(heightUpDown.Value);

I am using winforms in C#, in this case get the value from the text boxes and UpDown lists. How can I do it in c#?

Upvotes: 0

Views: 8039

Answers (4)

Rajat Singhal
Rajat Singhal

Reputation: 11

using the count to determine the Id may not work correctly if nodes are removed from the XML, during execution of the program.

Use Guid.NewGuid() instead to create a unique ID

Upvotes: 1

Selman Gen&#231;
Selman Gen&#231;

Reputation: 101701

You can use LINQ to XML for that.First get the current element count, then insert a new element like this:

var xDoc = XDocument.Load("path");
var count = xDoc.Descendants("user").Count();
var newUser = new XElement("user",
                  new XElement("id", count+1),
                  new XElement("name", nameBox.Text),
                  new XElement("surname", surnameBox.Text),
                  new XElement("weight", weightUpDown.Value),
                  new XElement("height", heightUpDown.Value));
xDoc.Root.Add(newUser);
xDoc.Save(path);

I would suggest you to get element count first (maybe in Form_load) then store it into a variable.By doing that you don't need to perform this query each time you want to add new item.You just need to increment the count.

Upvotes: 4

L.B
L.B

Reputation: 116168

You can get the max id as follows:

var maxId = xmlDoc.SelectNodes("/users/user/id")
                .Cast<XmlNode>()
                .Max(node => int.Parse(node.InnerText));

Upvotes: 1

blot
blot

Reputation: 23

I think I need some more information...

At first glance it looks like you will need to do the following:

  1. Iterate / loop through the values in text boxes and/or UpDown Lists.
  2. Make sure your loop has a counter variable that is created outside of the loop "int counter = 1".
  3. For each item you are iterating through use the counter to set the id in the xml you are generating.
  4. Before the item goes back to looping you should then increment the counter + 1.

You will be auto-populating each node with the values anyways correct?

All you will need is to add this counter variable and you should have basically what you need.

Upvotes: 0

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