How can i use ViewFieldsOverride property in CQWP Programatically? It will be great if with example

Question

I am creating ContentQuery Webpart programatically, To improve the performance i am following the below post(http://blogs.msdn.com/b/mimorr/archive/2009/11/19/improve-performance-of-content-query-web-parts-using-viewfieldsoverride.aspx). I would like to know, how to use ViewFieldsOverride property in CQWP programatically.

Answer 1

How to set ContentByQueryWebPart.ViewFieldsOverride property programatically (example):

cbq.ViewFieldsOverride = "<FieldRef ID=\"{fa564e0f-0c70-4ab9-b863-0177e6ddd247}\" Nullable=\"True\" Type=\"Text\" /><FieldRef ID=\"{94f89715-e097-4e8b-ba79-ea02aa8b7adb}\" Nullable=\"True\" Type=\"Lookup\" /><ProjectProperty Name=\"Title\" />";

Example:

        public static void AddDiscussionAggregatorWebPart(SPWeb web, string pageUrl, string zoneId, int zoneIndex)
        {
            using (var cbq = new ContentByQueryWebPart())
            {
                cbq.Title = "Latest Discussions";
                cbq.SortByDirection = ContentByQueryWebPart.SortDirection.Desc;
                cbq.ContentTypeBeginsWithId = "0x012002"; //Discussion Content Type
                cbq.SortBy = "{28cf69c5-fa48-462a-b5cd-27b6f9d2bd5f}";
                cbq.WebUrl = "~sitecollection";
                cbq.ServerTemplate = "108";  //Discussion Board List Type
                cbq.ViewFieldsOverride = "<FieldRef ID=\"{fa564e0f-0c70-4ab9-b863-0177e6ddd247}\" Nullable=\"True\" Type=\"Text\" /><FieldRef ID=\"{94f89715-e097-4e8b-ba79-ea02aa8b7adb}\" Nullable=\"True\" Type=\"Lookup\" /><ProjectProperty Name=\"Title\" />";

                AddWebPartOnPage(web, pageUrl, zoneId, zoneIndex, cbq);
            }
        }


        public static void AddWebPartOnPage(SPWeb web, string pageUrl, string zoneId, int zoneIndex, WebPart webPart)
        {
            var page = web.GetFile(pageUrl);
            using (var wpm = page.GetLimitedWebPartManager(PersonalizationScope.Shared))
            {
                try
                {
                    wpm.AddWebPart(webPart, zoneId, zoneIndex);
                    wpm.SaveChanges(webPart);
                }
                finally
                {
                    wpm.Web.Dispose();
                }
            }
        }