XmlReader Class

public static async Task ReadStartElementAsync(this XmlReader reader, string localname, string ns) {
 if (await 
   reader.MoveToContentAsync() != 
   XmlNodeType.Element) {
 throw new 
InvalidOperationException(
reader.NodeType.ToString() + " is an invalid XmlNodeType");
   }
 if (reader.LocalName == 
     localname && 
     reader.NamespaceURI == ns) {
 await reader.ReadAsync();
   }
 else {
 throw new InvalidOperationException("localName or namespace doesn’t match");
    }
}

public static async Task ReadEndElementAsync(this XmlReader reader) {
if (await reader.MoveToContentAsync() != XmlNodeType.EndElement) {
    throw new InvalidOperationException();
   }
 await reader.ReadAsync();
}

public static async Task<bool> ReadToNextSiblingAsync(this XmlReader reader, string localName, string namespaceURI) {
 if (localName == null || 
    localName.Length == 0) {
 throw new ArgumentException ("localName is empty or null");
   }
 if (namespaceURI == null) {
 throw new ArgumentNullException("namespaceURI");
   }

// atomize local name and namespace
   localName = 
    reader.NameTable.Add(localName);
   namespaceURI = 
   reader.NameTable.Add(namespaceURI);

// find the next sibling
 XmlNodeType nt;
 do {
 await reader.SkipAsync();
 if (reader.ReadState !=
 ReadState.Interactive)
 break;
      nt = reader.NodeType;
 if (nt == XmlNodeType.Element &&
      ((object)localName == 
      (object)reader.LocalName) && 
      ((object)namespaceURI == 
      (object)reader.NamespaceURI)) {
 return true;
       }
   }while(nt != XmlNodeType.EndElement 

   && !reader.EOF);
 return false;
}

public static async Task<bool> ReadToFollowingAsync(this XmlReader reader, string localName, string namespaceURI) 
{
 if (localName == null || 
     localName.Length == 0) {
 throw new 
     ArgumentException(
     "localName is empty or null");
   }
 if (namespaceURI == null) {
 throw new 
      ArgumentNullException(
     "namespaceURI");
}

// atomize local name and namespace
   localName = 
    reader.NameTable.Add(localName);
   namespaceURI = 
   reader.NameTable.Add(namespaceURI);

// find element with that name
 while (await reader.ReadAsync()) {
 if (reader.NodeType == XmlNodeType.Element && ((object)localName == (object)reader.LocalName) && ((object)namespaceURI == (object)reader.NamespaceURI)) {
 return true;
      }
   }
 return false;
}

public static async Task<bool> ReadToDescendantAsync(this XmlReader reader, string localName, string namespaceURI) {
 if (localName == null || localName.Length == 0) {
 throw new ArgumentException("localName is empty or null");
   }
 if (namespaceURI == null) {
 throw new ArgumentNullException("namespaceURI");
   }
 // save the element or root depth
 int parentDepth = reader.Depth;
 if (reader.NodeType != XmlNodeType.Element) {
 // adjust the depth if we are on root node
if (reader.ReadState == ReadState.Initial) {
    parentDepth--;
   }
else {
     return false;
       }
   }
else if (reader.IsEmptyElement) {
   return false;
}

// atomize local name and namespace
localName = reader.NameTable.Add(localName);
namespaceURI = reader.NameTable.Add(namespaceURI);

// find the descendant
while (await reader.ReadAsync() && reader.Depth > parentDepth) {
if (reader.NodeType == XmlNodeType.Element && ((object)localName == (object)reader.LocalName) && ((object)namespaceURI == (object)reader.NamespaceURI)) {
 return true;
}
}
return false;
}