C#缺省参数可以让代码变得更加简洁明了与时俱进心里敞亮了很多了

        public DataTable Search(string search)
        {
            return Search(string.Empty, search, null, null, string.Empty);
        }

        public DataTable Search(string search, string[] roleIds)
        {
            return Search(string.Empty, search, roleIds, null, string.Empty);
        }

        public DataTable Search(string search, string[] roleIds, bool? enabled)
        {
            return Search(string.Empty, search, roleIds, null, string.Empty);
        }

        public DataTable Search(string search, string[] roleIds, string auditStates)
        {
            return Search(string.Empty, search, roleIds, null, auditStates);
        }

        public DataTable Search(string search, string[] roleIds, bool? enabled, string auditStates)
        {
            return Search(string.Empty, search, roleIds, enabled, auditStates);
        }

        public DataTable Search(string search = null, string[] roleIds = null, bool? enabled = true, string auditStates = null)
        {
            return Search(string.Empty, search, roleIds, enabled, auditStates);
        }