我的排序没有正确返回

Question

有人可以指出为什么我的排序不起作用吗？我没有收到错误，方法只返回未排序的列表。

public IEnumerable<Customer> GetSubsetOfEmployees(int startRows, int maxRows, string sortExpression)
{
    NorthwindEntities ndc = new NorthwindEntities();
    var customerQuery =
        from c in ndc.Customers
            //https://code.msdn.microsoft.com/101-LINQ-Samples-3fb9811b
        select c;

    if (string.IsNullOrEmpty(sortExpression)) sortExpression = "CustomerID";

    Dictionary<string, Func<IEnumerable<Customer>, IEnumerable<Customer>>> orderings = new Dictionary<string, Func<IEnumerable<Customer>, IEnumerable<Customer>>>()
    {
        { "CustomerID",  x1 => x1.OrderBy(x => x.CustomerID) },
        { "CompanyName",  x1 => x1.OrderBy(x => x.CompanyName) },
        { "CustomerID DESC",  x1 => x1.OrderByDescending(x => x.CustomerID) },
    };

    orderings[sortExpression](customerQuery.Skip(startRows).Take(maxRows));

    return customerQuery;
}

Answer 1

您没有返回已排序的集合。

IEnumerable<Customer> result = orderings[sortExpression](customerQuery.Skip(startRows).Take(maxRows));
return result;