CODEWITHSUNDEEP
c#xmlxpath
DaMaGeX
DaMaGeX

Reputation: 763

How to get the attribute value of a XML node using XPath

This is my script, but it only prints spaces in the console. Can someone explain how I can get the attribute values from a XML file using xPath?

    XPathNavigator nav;
    XPathDocument docNav;
    XPathNodeIterator NodeIter;
    XmlNamespaceManager ns;

    Int32 elementCount;

    String windowName;

    private void Form1_Load(object sender, EventArgs e)
    {
        docNav = new XPathDocument("C:/BlueEyeMacro/DaMaGeX/Applications/WindowBuilder/GUI.xml");
        nav = docNav.CreateNavigator();
        ns = new XmlNamespaceManager(nav.NameTable); 
        elementCount = nav.Select("/GUI/window").Count;
        Console.WriteLine(elementCount);
        for (int i = 1; i <= elementCount; i++)
        {
            NodeIter = nav.Select("/GUI/window[@ID="+i+"]");
            windowName = NodeIter.Current.GetAttribute("name", ns.DefaultNamespace);
            Console.WriteLine("{0}", windowName);
        }
    }
}

XML File
<GUI>
<window ID="1" name="mainWindow" parent="0" type="0" text="My first window" options="Option 1;" actions="action 1;" exit="exit;" />
<window ID="2" name="secondWindow" parent="0" type="0" text="My second window" options="Option 1;" actions="action 1;" exit="exit;" />
<window ID="3" name="thirdWindow" parent="0" type="0" text="My third window" options="Option 1;" actions="action 1;" exit="exit;" />
</GUI>

Upvotes: 2

Views: 2547

Answers (3)

Dimitre Novatchev
Dimitre Novatchev

Reputation: 243459

You can directly obtain the string value of the attribute:

    for (int i = 1; i <= elementCount; i++) 
    { 
     // This obtains the value of the @name attribute directly
     string val = 
               nav.Evaluate("string(/GUI/window[@ID='"+i+"']/@name)") as string;                
     Console.WriteLine(val); 
    }

Upvotes: 1

dash
dash

Reputation: 91462

You can also modify your code to do this:

    for (int i = 1; i <= elementCount; i++) 
    { 
        var NodeIter = nav.SelectSingleNode("/GUI/window[@ID='"+i+"']/@name"); //This selects the @name attribute directly
        Console.WriteLine("{0}", NodeIter.Value); 
    }

Given you are identifying a node by a unique id, SelectSingleNode is a better fit for what you are trying to do.

Upvotes: 0

Markus Meyer
Markus Meyer

Reputation: 171

I guess, you have to call NodeIter.MoveNext() first like in this code:

XPathNodeIterator nodesText = nodesNavigator.SelectDescendants(XPathNodeType.Text, false);

while (nodesText.MoveNext())
{
    Console.Write(nodesText.Current.Name);
    Console.WriteLine(nodesText.Current.Value);
}

Upvotes: 3

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