Type t=typeof(类名);
MemberInfo[] members=t.GetMembers();
foreach(MemberInfo nextMember in members)
{
    if(nextMember.DeclaringType==typeof(String) && nextMember.MemberType== MemberTypes.Property)
    //do something
}

------解决方案--------------------
C# code

                Type type=typeof(myclass);
                System.Reflection.PropertyInfo[] pis=type.GetProperties();
                foreach (System.Reflection.PropertyInfo pi in pis)
                {
                    if (pi.GetType().Name == "string")
                    {
                        .....
                    }
                }