Question

For modifying the csproject file of mvc project, I used the code snippet like below, but failed to achieve it. could you please help me?

 var newReference = @"System.Web.Mvc, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL";

var profiles = Directory.GetFiles(path, "*.csproj", SearchOption.AllDirectories);

        foreach (var profile in profiles)
        {
            var doc = XDocument.Load(profile);
            var parentElement = doc.Descendants("ItemGroup").FirstOrDefault();
            if (parentElement != null)
            {
                var newNode = new XElement("Reference", new XAttribute("Include", newReference));
                parentElement.Add(newNode);
            }
            doc.Save(profile);
        }         

Answer 1

The “naive” answer is that you have to include the xml’s namespace

var newReference = @"System.Web.Mvc, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL";

var profiles = Directory.GetFiles(path, "*.csproj", SearchOption.AllDirectories);
var ns = XNamespace.Get("http://schemas.microsoft.com/developer/msbuild/2003");

foreach (var profile in profiles)
{
    var doc = XDocument.Load(profile);
    var parentElement = doc.Descendants(ns + "ItemGroup").FirstOrDefault();
    if (parentElement != null)
    {
        var newNode = new XElement("Reference", new XAttribute("Include", newReference));
        parentElement.Add(newNode);
    }
    doc.Save(profile);
}    

This will do what you try to achieve (adding a new reference in the first ItemGroup Element), but if you look at a csproj file, you’ll see that there’s not only one ItemGroup “group” !