I'm try to make a generic sort function to sort my class- "GiaoTrinh" by attribute price_GT use delegate. In class GiaoTrinh i created a function that called is CheckPrice to compare price between to object.In class ListGiaoTrinh i created a delegate and function GenericSort with parameters is List<object>.When i call GenericSort function the error is :

"cannot convert from Generic.List<GiaoTrinh> to Generic.List<object>.

How can i resolve it

class GiaoTrinh:IGiaoTrinh
    {
        private int id_GT;
        private string name_GT;
        private string tacGia;
        private int namXuatBan;
        private double price_GT;
 public static bool CheckPrice(object a,object b)
    {
        if (((GiaoTrinh)a).Price_GT < ((GiaoTrinh)b).Price_GT)
            return true;
        else
            return false;
    }
}

Code in class ListGiaoTrinh:

 class ListGiaoTrinh:IListGiaoTrinh
{
    public delegate bool compare(object o1, object o2);
    public static void GenericSort(List<object>obj, compare cmp)
    {
        for (int i = 0; i < obj.Count - 1; i++)
            for (int j = i + 1; j < obj.Count; j++)
            {
                if (cmp(obj[i], obj[j]))
                {
                    object temp;
                    temp = obj[i];
                    obj[i] = obj[j];
                    obj[j] = temp;
                }
            }
    }
    private List<GiaoTrinh> listGiaoTrinh;
 public void Sort()
    {
        GenericSort(this.listGiaoTrinh, GiaoTrinh.CheckPrice);
        Show();
    }
}