继承通用List [英] Inheriting from generic List
问题描述
我认为我必须遗漏一些关于泛型的东西，或许只是关于
语法。我想从System.Collections.Generic派生一个MyList类，所以
它只能包含MyItem的实例。
没问题
class MyList< T> ：列表< T>
{
}
但这要求我使用MyList< MyItem>创建它myList = new
MyList< MyItem>（）我想隐藏列表类中的那一位，所以我可以调用MyList myList = new MyList（
） ）;
构造函数应该是什么样的？我认为它应该像
非法
类MyList：List< T>
{
public MyList（）：base（< T>）
{
}
}
，但显然不是！这是可能的还是我对仿制药的理解
完全错了？
（任何人都知道这方面的好基础？）
Andrew
I think I must be missing something about generics, perhaps just about the
syntax. I''d like to derive a class MyList from System.Collections.Generic so
that it can only contain instance of MyItem.
No problem with
class MyList<T> : List<T>
{
}
but that requires me to create it with MyList <MyItem> myList = new
MyList<MyItem>() and I''d like to hide that bit in the list class itself so I
could call MyList myList = new MyList();
What should the constructor look like? I think it should be something like
the illegal
class MyList : List<T>
{
public MyList() : base (<T>)
{
}
}
but it obviously isn''t! Is this possible or is my understanding of generics
completely wrong?
(Anyone know a good primer on this?)
Andrew
推荐答案
" Andrew McLellan" <一个**** @ cix.co.uk> schrieb im Newsbeitrag
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"Andrew McLellan" <an****@cix.co.uk> schrieb im Newsbeitrag
news:e5*************@TK2MSFTNGP10.phx.gbl...
我想我一定不能错过关于泛型的东西，也许只是关于
语法。我想从System.Collections.Generic派生一个MyList类，以便它只能包含MyItem的实例。
类没问题MYLIST< T> ：列表< T>
但是这需要我用MyList< MyItem>创建它。 myList = new
MyList< MyItem>（）我想在列表类本身中隐藏该位，以便我可以调用MyList myList = new MyList（）;
构造函数应该是什么样的？我认为它应该是类似
非法
类MyList：List< T>
公共MyList（）：base（< T>）
{
}
}
但显然不是！这是可能的还是我对
泛型完全错误的理解？
（任何人都知道这方面的好基础吗？）
Andrew
I think I must be missing something about generics, perhaps just about the
syntax. I''d like to derive a class MyList from System.Collections.Generic
so that it can only contain instance of MyItem.
No problem with
class MyList<T> : List<T>
{
}
but that requires me to create it with MyList <MyItem> myList = new
MyList<MyItem>() and I''d like to hide that bit in the list class itself so
I could call MyList myList = new MyList();
What should the constructor look like? I think it should be something like
the illegal
class MyList : List<T>
{
public MyList() : base (<T>)
{
}
}
but it obviously isn''t! Is this possible or is my understanding of
generics completely wrong?
(Anyone know a good primer on this?)
Andrew
您可以尝试：
class MyList：List< MyItem>
{
public MyList（）
{
}
}
由于MyList总是包含MyItem对象，因此它不是泛型类
本身。
You can try:
class MyList : List<MyItem>
{
public MyList()
{
}
}
Since MyList shall always contain MyItem-objects it''s no generic class
itself.
谢谢，正是我所追求的。
Andrew
Thank you, exactly what I was after.
Andrew
Andrew McLellan< an **** @ cix.co.uk>写道：
Andrew McLellan <an****@cix.co.uk> wrote:
谢谢，正是我所追求的。
Thank you, exactly what I was after.
但在那个阶段，为什么不使用List< MyItem>在你的代码？据我所知，没有必要在这里创建一个新类 - 除非你是否需要增加额外的功能。
-
Jon Skeet - < sk *** @ pobox.com>
http://www.pobox.com/~skeet 博客： http://www.msmvps.com/jon.skeet
如果回复该群组，请执行不要给我发邮件
But at that stage, why not just use List<MyItem> in your code? There''s
no need to create a new class here, as far as I can see - unless you''re
going to add extra functionality, of course.
--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too
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