数组到字典
我试图将此 _valueAdds = List 放入 gridItems （Dictionary），其中 _valueAdds 为键和所有值均为 false。但我不知道如何用 Lamda 做到这一点。这就是我在下面走了多远。我确实成功地用 while 循环做到了这一点，但想学习用 Lamda 做到这一点
gridItems = new Dictionary<ValueAddedItemHelper, bool>();
gridItems = _valueAdds.Select(k => new { k }).ToArray().ToDictionary(t => t, false);
I'm trying to get this _valueAdds = List<ValueAddedItemHelper> into gridItems (Dictionary) with _valueAdds being the Key and all the values being false. But I'm not sure how to do this with Lamda. This how far I got below. I did succeed in doing it with a while loop but would like learn to do it with Lamda
gridItems = new Dictionary<ValueAddedItemHelper, bool>();
gridItems = _valueAdds.Select(k => new { k }).ToArray().ToDictionary(t => t, false);
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您需要提供 lambda 表达式作为第二个参数（或以其他方式创建委托，但 lambda 表达式是最简单的）。请注意，对
ToArray的调用不是必需的，您要创建的空字典也不是必需的。只是使用：我不清楚为什么你在这里使用匿名类型......特别是，不会是一个
ValueAddedItemHelper。您是否需要投影？也许只是：You need to provide a lambda expression as the second argument (or create the delegate some other way, but a lambda expression will be simplest). Note that the call to
ToArrayisn't required, and nor is the empty dictionary you're creating to start with. Just use:It's not clear to me why you're using an anonymous type here though... in particular, that won't be a
ValueAddedItemHelper. Do you need the projection at all? Perhaps just:您不需要 ToArray().ToDictionary()。您只需执行 ToDictionary() 即可。而且你不需要第一行。第二行将创建并填充字典。
代码：
You don't need a ToArray().ToDictionary(). You can simply do a ToDictionary(). And you don't need the first line. The second line will create and fill the dictionary.
The code:
假设
_valueAdds是IEnumerable你可以这样做：Assuming
_valueAddsis anIEnumerable<ValueAddedItemHelper>you could do this:像这样的东西
Something like
Select(k => new { k })是问题所在；它创建一个带有名为k的属性的匿名类型。只是：The
Select(k => new { k })is the problem; that creates an anonymous type with a property calledk. Just: