xmltextreader not reading xml file content

I have try to show the xml content in to textbox in MainWindow loaded event. But i couldn't read the content in xml file which was always shown as empty

            XmlRootAttribute xRoot = new XmlRootAttribute();
            xRoot.ElementName = "string";
            xRoot.IsNullable = true;

            XmlSerializer deserialization = new XmlSerializer(typeof(string),xRoot);
            XmlTextReader textReader = new XmlTextReader(@"D:\text.xml");
            textReader.Read();
            while (textReader.Read())
            {
                XmlNamespaceManager nsmgr = new XmlNamespaceManager(textReader.NameTable);
                nsmgr.AddNamespace("", "");

                if (textReader != null)
                    deserialization.Deserialize(textReader);
            }

            textReader.Close();