你如何处理IDisposableobject的创建一个LINQ EX pression里面？ [英] How do you dispose of IDisposableobject create inside of a Linq expression?

问题描述

的LINQ允许你创建新的对象的查询EX pression内。当你有一个封装列表生成类中这是非常有用的。我想知道你是如何处理那些需要它创建的对象呢？

Linq allows you to create new object inside of a query expression. This is useful when you have classes that encapsulate generation of a list. I’m wondering how you dispose of objects that are created that need it?

例如：

class Generator
{
    public IEnumerable<int> Gen(int size)
    {
        return Enumerable.Range(0, size);
    }
}

class bar
{
    public void doit()
    {
        var foo =
            from r in Enumerable.Range(1, 3)
            from g in new Generator().Gen(r)
            select g;
    }
}

这将创建3个发电机对象将被垃圾在某些时候收集。如果发电机是IDisposable的我怎么会得到的Dispose（）调用？

This will create 3 Generator objects that will be garbage collected at some point. If Generator was IDisposable how would I get the Dispose() call?

推荐答案

确定;我希望这是巧合，而是：的SelectMany;结合了IDisposable和LINQ ，这（与自定义的SelectMany 实施）将允许：

OK; I'm hoping this is coincidence, but: SelectMany; combining IDisposable and LINQ, which (with the custom SelectMany implementation) would allow:

    var foo =
        from r in Enumerable.Range(1, 3)
        from gen in new Generator()
        from g in gen.Gen(r)
        select g;

（注意，我的假设的存在是一个明智的理由，每做研究）

(note that I'm assuming there is a sensible reason to do this per r)

或与使用（）扩展方法（而不是的SelectMany ）：

or with the Using() extension method (instead of SelectMany):

    var foo =
        from r in Enumerable.Range(1, 3)
        from gen in new Generator().Using()
        from g in gen.Gen(r)
        select g;

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