<?xml version="1.0" encoding="UTF-8"?>
<summary>
  <testresult>
    <result value="10" name="long">100</result>
    <result value="12" name="short">200</result>
    <result value="14" name="long">300</result>
  </testresult>
  <testresult>
    <result value="10" name="short">50</result>
    <result value="12" name="short">60</result>
    <result value="14" name="long">70</result>
  </testresult>
</summary>

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(item.Value);
XmlNodeList nodelist = xmlDoc.SelectNodes("//testresult");

for (int i = 0; i < nodelist.Count; i++)
{
    foreach (XmlElement child in nodelist[i])
    {
        if (child.HasAttributes)
        {
            result.Add(child.Attributes["value"].Value); //This is working fine.
        }
    }
}