Find an attribute that contains a ceratin string and modifying its Value in c# using LINQ

Question

Hello,

I'm trying to find the first attribute in an xml file that contains the string "name" (case insensitve) in it and then change its value.

Here is an example of my xmls

//XML 1
<CtApproachTypes  
 DataclassId="1992A9CE-B048-4676-BFD4-FD81F1A65401"  
 EntityId="1992A9CE-B048-4676-BFD4-FD81F1A65401"  
 Name="PAR"  
 Remark="No Remarks"></CT_ApproachTypes> 

//XML 2
<MiMissions  
 DataclassId="C196A66B-4FA1-461C-9EEF-95A4F2085051"  
 EntityId="C196A66B-4FA1-461C-9EEF-95A4F2085051"  
 MissionName="Standard" 
 Visib="1"></MiMissions> 

//XML 3
<StSituations  
 DataclassId="679FAC3C-C9EF-41FD-9A13-957915605F01"  
 EntityId="679FAC3C-C9EF-41FD-9A13-957915605F01"  
 Sname="Standard"  
 Status="C"  
 Template="1"></StSituations> 

I wanna be able to modify the values of "Name", "MissionName", "Sname", and print them out to console

EDIT here is my code

        public void updateXmlFile(string strFileName)
    {
        try
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(strFileName);

            string newValue = GetUniqueKey();

            XmlNodeList list = doc.SelectNodes("@*"); 
            IEnumerable<XmlNode> filteredList= list.Cast<XmlNode>().Where(item=>item.Value.ToLower().Contains("name"));

            foreach (XmlNode n in filteredList)
            {
                Console.WriteLine("NODES ARE : {0}", n);
            }
                doc.Save(strFileName);

        }
        catch (XmlException xex) { Console.WriteLine(xex); }

    }

This didn't print out anything and I need still to modify the original value with the string newValue

Answer 1

What you could do, is first select all XML attributes, then use LINQ to select all attributes containing 'Name'.

XmlDocument document = new XmlDocument();
...
XmlNodeList list = document.SelectNodes("@*");
IEnumerable<XmlNode> filteredList= list.Cast<XmlNode>().Where(item=>item.Value.ToLower().Contains("name"));

I hope this points you in the right direction.

Edit:

Reda, you were absolutely right, I made some mistakes. This code worked on my machine ;-) I added comments where I altered your code.

    public void updateXmlFile(string strFileName)
    {
        try
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(strFileName);

            string newValue = GetUniqueKey();

            XmlNodeList list = doc.SelectNodes("//@*"); // Forgot the slashes here...
            IEnumerable<XmlNode> filteredList = list.Cast<XmlNode>().
                Where(item => item.Name.ToLower().Contains("name")); // Name property instead of Value

            foreach (XmlNode n in filteredList)
            {
                n.Value = newValue; // Setting the value.
                Console.WriteLine("FILTERED NODES ARE : {0}", n.Value);
            }

            doc.Save(strFileName);

        }
        catch (XmlException xex) { Console.WriteLine(xex); }

    }

Answer 2

I would use the XDocument object, because it is easy to query with linq. It's in the System.Xml.Linq namespace and assembly.

public void updateXmlFile(string strFileName)
{
    XDocument xDoc = XDocument.Load(strFileName);

    var nameAttributes = from el in xDoc.Root.Elements()
                         from attr in el.Attributes()
                         where attr.Name.ToString().ToLower().Contains("name")
                         select attr;

    foreach (var attribute in nameAttributes)
    {
        attribute.Value = "newValue";
        Console.WriteLine("{0}: {1}", attribute.Name, attribute.Value);
    }

    xDoc.Save(strFileName);
}

Update

This is the output, given the XML in your example if it is saved into a single file:

Name: newValue
MissionName: newValue
Sname: newValue