A PageList: A page control on WPF

I create a page control used to data access and display a page which own defined. It used the entityframework4.1 as data access and IQuerable<T> handle the page it's mechism.

The code is:

   public class PagedList<T> : List<T> {
        public int StartIndex { get; private set; }
        public int PageSize { get; private set; }
        public int TotalCount { get; private set; }
        public int PageCount {
            get {
                if ((TotalCount % PageSize) > 0)
                    return (TotalCount / PageSize) + 1;
                else
                    return TotalCount / PageSize;
            }
        }

        private PagedList(IEnumerable<T> pagedList, int startIndex, int pageSize, int totalCount)
            : base(pagedList) {
            StartIndex = startIndex;
            PageSize = pageSize;
            TotalCount = totalCount;
        }

        public PagedList(IQueryable<T> dataSource, int startIndex, int pageSize)
            : base(dataSource.Skip(startIndex).Take(pageSize)) {
            StartIndex = startIndex;
            PageSize = pageSize;
            TotalCount = dataSource.Count();
        }

        public PagedList<TResult> Transform<TResult>(Func<T, TResult> selector) {
            return new PagedList<TResult>(this.Select(selector), StartIndex, PageSize, TotalCount);
        }
    }