how to write extension method for paging in mvc

问题

i've define static class to enable paging :

public static class Pager
{
   public static IEnumerable<T> PageData<T>(this IEnumerable<T> source, int currentPage, int pageSize)
   {
       var sourceCopy = source.ToList();

       if (sourceCopy.Count() < pageSize)
       {
            return sourceCopy;
       }

       return sourceCopy.Skip((currentPage - 1) * pageSize).Take(pageSize);
   }
}

and i want in my controller to do like :

var pagedDataCourses = products.OrderBy(p => p.productName).PageData(currentPage, pageSize);

so where i can put that static class/method so i can get extension method for paging in all controller.

回答1:

public static IQueryable<T> Page<T>(this IQueryable<T> query, int page, int pageSize)
{
   int skip = Math.Max(pageSize * (page - 1), 0);
   return query.Skip(skip).Take(pageSize);
}

You will have to put it in the same namespace as where you are using the extension. Or us the "using" at the top of your .cs files