/// <summary>
        /// Set 属性值
        /// </summary>
        /// <param name="target">拥有该成员的类实例</param>
        /// <param name="value">字段/属性值</param>
        public override void Set(object target, object value)
        {
            if (!_member.CanWrite)
            {
                throw new XfwException("this property [{0}] is unwritable", base.FullName);
            }

            _setter = _setter ?? MemberAccess_Property.InitializeSetter(_member);
            _setter(target, value ?? Helper.GetNullValue(_member.PropertyType));
        }
        /// <summary>
        /// Get 属性值
        /// </summary>
        /// <param name="target">拥有该成员的类实例</param>
        /// <returns></returns>
        public override object Get(object target)
        {
            if (!_member.CanRead)
            {
                throw new XfwException("this property [{0}] is unreadable", base.FullName);
            }

            _getter = _getter ?? MemberAccess_Property.InitializeGetter(_member);
            return(_getter(target));
        }