Using Sharepoint List Webservice

Sharepoint exposes some really useful webservices. One among the most useful is the List Webservices.

We can take the webreference from the following location

http://mossserver/_vti_bin/lists.asmx

Once we have added the webservice, we can use following generic method to call webservice

XmlNode CallWebService(bool isRecursive, ListsService listService,
string listName, string queryObj, string viewID, string viewFieldsInnerXml)
{
  try
  {
      NetworkCredential credential = new NetworkCredential();
      credential.UserName = "UserName";
      credential.Password = "Password";
      credential.Domain = "Domain";
      listService.Credentials = credential;

      // Instantiate an XmlDocument object
      System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
   
      string viewName = string.Empty;
      if (string.Empty != viewID)
      {
          viewName = viewID;
      }
      string rowLimit = "150";

      System.Xml.XmlElement query = xmlDoc.CreateElement("Query");
      System.Xml.XmlElement viewFields = xmlDoc.CreateElement("ViewFields");
      System.Xml.XmlElement queryOptions = xmlDoc.CreateElement("QueryOptions");

      if (isRecursive)
          queryOptions.InnerXml = "<ViewAttributes Scope=\"Recursive\" />";
      else
          queryOptions.InnerXml = "";

      if (string.Empty == queryObj)
      {
          query.InnerXml = "<Where><Gt><FieldRef Name=\"ID\" />" +
                              "<Value Type=\"Counter\">0</Value></Gt></Where>";
      }
      else
      {
          query.InnerXml = queryObj;
      }

      // Assign View fields
      if (string.Empty != viewFieldsInnerXml)
      {
          viewFields.InnerXml = viewFieldsInnerXml;
      }
      else
      {
          viewFields.InnerXml = "<FieldRef Name=\"Title\" />";
      }
      System.Xml.XmlNode nodeListItems =
          listService.GetListItems(listName, viewName, query,
viewFields, rowLimit, queryOptions, null);

      return nodeListItems;
  }
  catch (Exception ex)
  {
      throw ex;
  }
}

You can use this generic method for getting the list items.

Pass true to “IsRecursive” if you want to get items inside folder.

Example:

string fields = "<FieldRef Name=\"FieldName1\" />
<FieldRef Name=\"FieldName2\" />";
XmlNode nodeListItems = CallWebService(true, l, "Answer Choices",
string.Empty, string.Empty, fields);

foreach (System.Xml.XmlNode listItem in nodeListItems)
{
   if (listItem.ChildNodes.Count > 0)
   {
       foreach (XmlNode node in listItem.ChildNodes)
       {
           string choice = node.Attributes["ows_Title"]
.Value;               
       }
   }
}