只读关键字不使List<>只读？ [英] readonly keyword does not make a List<> ReadOnly?

问题描述

我有一个公共静态类下面的代码：

I have the following code in a public static class:

public static class MyList
{
    public static readonly SortedList<int, List<myObj>> CharList;
    // ...etc.
}

..但即使使用只读我仍然可以从其他类项目添加到列表中：

.. but even using readonly I can still add items to the list from another class:

MyList.CharList[100] = new List<myObj>() { new myObj(30, 30) };

或

MyList.CharList.Add(new List<myObj>() { new myObj(30, 30) });

有没有一种方法，使读的东西只有在不改变CharList的实现（它会打破一些东西）？
。如果我必须改变实现（使它不可更改），这将是最好的方法是什么？
我需要它是List< T，T>中这样ReadOnlyCollection还不会做。

Is there a way to make the thing read only without changing the implementation of CharList (it'll break some stuff)? If I do have to change the implementation (to make it non-changeable), what would be the best way? I need it to be List<T, T>, so ReadOnlyCollection won't do

推荐答案

的修改< A HREF =htt​​p://msdn.microsoft.com/en-us/library/acdd6hb7.aspx> 只读 意味着该值不能分配的除了在声明或构造函数。它的不的意思是分配的对象将成为不可改变的。

The modifier readonly means that the value cannot be assigned except in the declaration or constructor. It does not mean that the assigned object becomes immutable.

如果你希望你的对象是不可变的，你必须使用一个类型，是不可变的。类型 ReadOnlyCollection还< T> 了你提到的是一个不可改变的集合的一个例子。请参阅如何实现相同的字典此相关的问题：

If you want your object to be immutable, you must use a type that is immutable. The type ReadOnlyCollection<T> that you mentioned is an example of a immutable collection. See this related question for how to achieve the same for dictionaries:

• 的是否有在.NET中可用的只读通用字典？

• Is there a read-only generic dictionary available in .NET?

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