17.6.3 Virtual, sealed, override, and abstrac
日期:2007年5月3日 作者: 查看:[大字体 中字体 小字体]-
A virtual property declaration specifies that the accessors of the property
are virtual. The virtual modifier
applies to both accessors of a read-write property?it is not possible for
only one accessor of a read-write
property to be virtual.
An abstract property declaration specifies that the accessors of the
property are virtual, but does not provide an
actual implementation of the accessors. Instead, non-abstract derived
classes are required to provide their own
implementation for the accessors by overriding the property. Because an
accessor for an abstract property
declaration provides no actual implementation, its accessor-body simply
consists of a semicolon.
A property declaration that includes both the abstract and override
modifiers specifies that the property is
abstract and overrides a base property. The accessors of such a property
are also abstract.
Abstract property declarations are only permitted in abstract classes (§17.1
.1.1). The accessors of an inherited
virtual property can be overridden in a derived class by including a
property declaration that specifies an
override directive. This is known as an overriding property declaration. An
overriding property declaration
does not declare a new property. Instead, it simply specializes the
implementations of the accessors of an existing
virtual property.
An overriding property declaration must specify the exact same
accessibility modifiers, type, and name as the
inherited property. If the inherited property has only a single accessor
(i.e., if the inherited property is read-only
or write-only), the overriding property must include only that accessor. If
the inherited property includes both
accessors (i.e., if the inherited property is read-write), the overriding
property can include either a single accessor
or both accessors.
An overriding property declaration may include the sealed modifier. Use of
this modifier prevents a derived
class from further overriding the property. The accessors of a sealed
property are also sealed.
Except for differences in declaration and invocation syntax, virtual,
sealed, override, and abstract accessors
behave exactly like virtual, sealed, override and abstract methods.
Specifically, the rules described in §17.5.3,
§17.5.4, §17.5.5, and §17.5.6 apply as if accessors were methods of a
corresponding form:
? - [1] [2] 下一页
-
- 17.6.3 Virtual, sealed, override, and abstrac 相关文章:
- ·17.6.3 Virtual, sealed, override, and abstrac
- 17.6.3 Virtual, sealed, override, and abstrac 相关软件
- 特别声明:本站除部分特别声明禁止转载的专稿外的其他文章可以自由转载,但请务必注明出处和原始作
- 者.文章版权归文章原始作者所有.对于被本站转载文章的个人和网站,我们表示深深的谢意。如果本站转
- 载的文章有版权问题请联系编辑人员,我们尽快予以更正. 转载请注明来源:http://www.hackhome.com
上一篇:J2ME手机游戏引擎程序结构简述
下一篇:本周技术关注[面向webapps运维]:Build Your Own Oracle RAC 10g Release 2 Cluster on Linux and FireWire
精品推荐
热点TOP10
- ·图象处理中的边缘检测------canny算子
- ·EZ-USB 68013A开发指南
- ·数值计算程序大放送-特征值和特征向量
- ·ARM的嵌入式Linux移植体验之BootLoader
- ·Visual C++ ADO数据库编程入门
- ·智能手机Smartphone开发导语
- ·利用 wordXP 实现自动排班
- ·[分形]DLA团簇模型的摸拟
- ·DENX U-Boot及Linux使用手册
- ·Static和Final修饰类属性变量及初始化
- ·BPEL的异常管理
- ·看Vue 5 Esprit函数的节点与链接详情
- ·初学者全面接触学习jquery(译文)
- ·LinQ学习之旅 从整型数组中找出偶数
- ·Enterprise Library 快速入门
- ·CVS源代码库服务器建立和权限配置
- ·Visual FoxPro 9.0 SP2正式版下载
- ·VS2005控件的问题解决办法
- ·Cookie是什么?用法是怎样?与SESSION有什么区别?
- ·J2SE API读取Properties文件的六种方法
