Why does deserializing my .config package in C # return null values?

Question

I am trying to deserialize my package.config file in C #, but the collection I get is always null. Is there anything special that is needed if my XML file consists of one set of attributes?

[Serializable()] [System.Xml.Serialization.XmlTypeAttribute()] public class Package { [System.Xml.Serialization.XmlAttribute("id")] public string Id {get;set;} [System.Xml.Serialization.XmlAttribute("version")] public string Version {get;set;} } [Serializable()] [System.Xml.Serialization.XmlRoot("packages")] public class PackageCollection { [System.Xml.Serialization.XmlArrayItem("package", typeof(Package))] public Package[] Packages {get;set;} } void Main() { var path = "C:\D\packages.config"; var serializer = new System.Xml.Serialization.XmlSerializer(typeof(PackageCollection), new System.Xml.Serialization.XmlRootAttribute("packages")); StreamReader reader = new StreamReader(file); var packages2 = (PackageCollection)serializer.Deserialize(reader); reader.Close(); } 

where my packages.config looks like

 <?xml version="1.0" encoding="utf-8"?> <packages> <package id="Autofac" version="3.3.1" targetFramework="net45" /> <package id="Microsoft.AspNet.WebApi.Client" version="4.0.20710.0" targetFramework="net45" /> <package id="Microsoft.AspNet.WebApi.Core" version="4.0.20710.0" targetFramework="net45" /> <package id="Microsoft.AspNet.WebApi.Tracing" version="4.0.30506" targetFramework="net45" /> <package id="Microsoft.Net.Http" version="2.0.20710.0" targetFramework="net45" /> <package id="Microsoft.Web.Infrastructure" version="1.0.0.0" targetFramework="net45" /> <package id="Newtonsoft.Json" version="4.5.11" targetFramework="net45" /> </packages> 

Answer 1

Use an XmlElement in this case:

 [Serializable()] [System.Xml.Serialization.XmlRoot("packages")] public class PackageCollection { [System.Xml.Serialization.XmlElement("package", typeof(Package))] public Package[] Packages { get; set; } } 

Answer 2

This code functions according to your needs based on the included testing:

 [Serializable()] [System.Xml.Serialization.XmlTypeAttribute()] public class Package { [System.Xml.Serialization.XmlAttributeAttribute("id")] public string Id { get; set; } [System.Xml.Serialization.XmlAttributeAttribute("version")] public string Version { get; set; } [System.Xml.Serialization.XmlAttributeAttribute("targetFramework")] public string TargetFramework { get; set; } } [Serializable()] [System.Xml.Serialization.XmlRoot("packages")] public class PackageCollection { [System.Xml.Serialization.XmlElementAttribute("package")] public Package[] Packages { get; set; } } class Program { static void Main() { var path = @"C:\packages.config"; var serializer = new System.Xml.Serialization.XmlSerializer(typeof(PackageCollection)); StreamReader reader = new StreamReader(path); var packages2 = (PackageCollection)serializer.Deserialize(reader); foreach (Package pkg in packages2.Packages) { Console.WriteLine("ID: " + pkg.Id); Console.WriteLine("Version: " + pkg.Version); Console.WriteLine("Target Framework: " + pkg.TargetFramework); Console.WriteLine(); } reader.Close(); Console.ReadLine(); } } 

As @Isantipov noted, XML Schema Definition Tool (Xsd.exe) - MDSN can be useful.

See also the question How to deserialize an XML document for more information, in particular Mark Gravell's answer .