从ObservableCollection继承的Collection-有什么好处?

问题描述

在查看了此MSDN文章之后，我现在想知道的是好处(如果有的话)是将集合定义为继承自 ObservableCollection 的类.两者之间有什么显着区别吗?

After looking at this MSDN article, I am now wondering what the benefit, if any, is of defining a collection as a class that inherits from ObservableCollection. Are there any significant differences between this:

class MyCollection : ObservableCollection<MyObject> { }

class Class1
{
    private MyCollection _newCollection = new MyCollection();

    public Class1()
    {
        _newCollection.Add(new MyObject());
    }
}

和这个:

class Class1
{
    private ObservableCollection<MyObject> _newCollection = new ObservableCollection<MyObject>();

    public Class1()
    {
        _newCollection.Add(new MyObject());
    }
}

这里有什么我可以俯瞰的地方吗?

Is there something I'm overlooking here?

推荐答案

一个主要好处是您可以定义 Add 函数，这使内联初始化更加容易.因此，例如:

One major benefit is that you can define the Add function, which makes inline initialization easier. So for example this:

class MyCollection : ObservableCollection<MyObject> 
{  
    public void Add(string prop1, string prop2)
    {
        base.Add(new MyObject { Prop1 = prop1, Prop2 = prop2 });
    }
}

让你这样写:

MyCollection collection = new MyCollection
{
    { "prop1", "prop2" },
    { "prop1", "prop2" },
};

第二个(相关的)好处:如果您正在使用XAML，拥有一个子类化的集合可让您将集合实例(用于设计/测试用例)定义为标记，如下所示:

A second (related) benefit: if you're working with XAML, having a subclassed collection lets you define collection instances (for design/test cases) as markup, as in:

<local:MyCollection xmlns:local="MyNamespace">
    <local:MyObject Prop1="prop1" Prop2="prop2" />
    <local:MyObject Prop1="prop1" Prop2="prop2" />
</local>

最后，(我想这只是一个口味问题)，它总体上不会受到伤害，并且可以提供帮助.有时，对于给定的集合类型，您最终需要更多的方法/属性.准备好一个类型化的子类，而无需重构很高兴.

Lastly, (and this is merely a matter of taste, I suppose) it doesn't hurt in general, and can help. Sometimes you end up needing more methods/properties for a given collection type. It's nice to have a typed subclass ready, without needing to refactor.

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