private static object GetPropertyValue(object obj, string property)

{

      System.Reflection.PropertyInfo propertyInfo = obj.GetType().GetProperty(property);

      return propertyInfo.GetValue(obj, null);

} 

var resultList = sortOrder == "desc" ? groupList.OrderByDescending(p => GetPropertyValue(p, sortName)) : groupList.OrderBy(p => GetPropertyValue(p, sortName));

//linq方式：

//

var resultList1 = from p in groupList orderby GetPropertyValue(p, m.SortName) select p;

if (sortOrder == "desc")

    resultList1 = from p in groupList orderby GetPropertyValue(p, sortName) descending select p;

var groupQueryList = groupList.AsQueryable();//here

var tmpList = groupQueryList.OrderBy(sortName, sortOrder);

    public static IOrderedQueryable<T> OrderByDescending<T>(this IQueryable<T> source, string property)

    {

        return ApplyOrder<T>(source, property, "OrderByDescending");

    }

    public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string property)

    {

        return ApplyOrder<T>(source, property, "ThenBy");

    }

    public static IOrderedQueryable<T> ThenByDescending<T>(this IOrderedQueryable<T> source, string property)

    {

        return ApplyOrder<T>(source, property, "ThenByDescending");

    }

    static IOrderedQueryable<T> ApplyOrder<T>(IQueryable<T> source, string property, string methodName) {

        string[] props = property.Split('.');

        Type type = typeof(T);

        ParameterExpression arg = Expression.Parameter(type, "x");

        Expression expr = arg;

        foreach(string prop in props) {

            // use reflection (not ComponentModel) to mirror LINQ

            PropertyInfo pi = type.GetProperty(prop);

            expr = Expression.Property(expr, pi);

            type = pi.PropertyType;

        }

        Type delegateType = typeof(Func<,>).MakeGenericType(typeof(T), type);

        LambdaExpression lambda = Expression.Lambda(delegateType, expr, arg);

        object result = typeof(Queryable).GetMethods().Single(

                method => method.Name == methodName

                        && method.IsGenericMethodDefinition

                        && method.GetGenericArguments().Length ==

                        && method.GetParameters().Length == )

                .MakeGenericMethod(typeof(T), type)

                .Invoke(null, new object[] {source, lambda});

        return (IOrderedQueryable<T>)result;

   }