How to find the Doctype is in xml file or not.

Question

Hi,

   I am developing a tool. that want to find the elements of xml file's and replace the contents. first i want ot find that the xml file contain DOCTYPE or not. if yes i want to change the values of that.

 

i tried this code. but got error,

 

 

var files = Directory.GetFiles(txtpath.Text);

foreach (var f in files)

{

//doc = XDocument.Load(f);

XmlDocument xmldoc = new XmlDocument();

xmldoc.LoadXml(f.Substring(f.IndexOf(Environment.NewLine))); // Error In this line.

var node = xmldoc.SelectSingleNode("//DOCTYPE");

if (node != null)

{

}

          //ele = XElement.Load(f);

}

 

how to do this. Thanks In Advance.