I made sample with ZOHO CRM API which have CURL and XML response which help you to understand in more about to learn xml and curl in asp.net.
Below is an example with Zoho CRM to get customer list in XML as response..
string strAuthToken = "Your Auth Token should be here";
var webAddr="https://crm.zoho.com/crm/private/xml/Contacts/getRecords?newFormat=1&authtoken=" + strAuthToken + "&scope=crmapi&fromIndex=1&toIndex=500&sortColumnString=Account%20Name&sortOrderString=desc";
var request = (HttpWebRequest)WebRequest.Create(webAddr);
request.ContentType = "application/xml; charset=utf-8";
request.Method = "GET";
var httpResponse = (HttpWebResponse)request.GetResponse();
string result = "";
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
result = streamReader.ReadToEnd();
//Create the XmlDocument.
XmlDocument doc = new XmlDocument()
Now here, doc object contain whole xml response which you can read by using XmlNodeList and their properties.
I hope this help you.