是否可能返回一个只读ObservableCollection，调用者不能修改？ [英] Is it possible to return a read-only ObservableCollection that the caller can't modify?

问题描述

请考虑以下代码：

public ObservableCollection<Message> Messages {
   get { return new ObservableCollection<Message>(); }
}

有什么我可以做，以防止调用者代码添加/删除/更改项目？

Is there anything I can do to prevent the caller code from adding/removing/changing items?

编辑：对不起，每个人，我只是注意到它是一个 dupe ，但接受的答案是错误的。

Sorry, everyone, I just noticed it's a dupe, but the accepted answer is wrong.

推荐答案

如何使用 ReadOnlyObservableCollection

代码将是：

public ReadOnlyObservableCollection<Message> Messages 
{
  get { return new ReadOnlyObservableCollection<Message>(new ObservableCollection<Message>()); }
}

阅读了 ReadOnlyObservableCollection反模式我意识到上面的是不是一个好的方法，可能会导致微妙的错误。建议的方法是：

Having read aboutReadOnlyObservableCollection Anti Pattern I realise the above is the not a good approach and may lead to subtle bugs. The suggested approach is:

public class MyClass
{
  public MyClass()
  {
    myCollection = new ObservableCollection<Message>();
    myReadOnlyCollection = new ReadOnlyObservableCollection<Message>(myCollection);
  }

  public ReadOnlyObservableCollection<Message> Messages 
  {
    get { return myReadOnlycollection; }
  }

  private readonly ObservableCollection<Message> myCollection;
  private readonly ReadOnlyObservableCollection<Message> myReadOnlyCollection;
}

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