使用该lambda中包含的匿名类型定义lambda表达式(Defining a lambda expression with an anonymous type contained within that lambda)

 我试图避免在我的lambda表达式中使用动态类型来分组集合。 该类型在编译时是匿名定义的（据我所知，这是明确的）。 我宁愿不将类型定义为一个完整的类，因为我在这个单一方法中只使用了几次。 
 
 示例代码： 
 
Func<MyData, dynamic> dataGrouping = md => new
    {
        md.Property1,
        md.Property2,
        md.Property3
    };

var groupedData = myDataCollection.GroupBy(dataGrouping);
 
 虽然这会编译，但由于类型是动态的，因此在组内部没有智能感知或强类型。 
 
 我不能将dataGrouping的类型指定为var，因为我在C＃中，我得到的抱怨是不能将lambda表达式分配给隐式类型的局部变量 。 
 
 我可以用匿名类型的GetType（）替换动态吗？ 然后我需要在lambda中使用它之前的类型，但在我已经进入lambda本身之前，我看不到一个有用的方法来获取它。 
 
 有没有一种优雅的方式来获得这个匿名类的类型？ 

I'm trying to avoid a dynamic type in my lambda expression for grouping a collection. The type is defined anonymously at compile time (and unambiguously as far as I can tell). I'd rather not define the type as a full-fledged class as I'm only using it a few times in this single method.
 
Sample code:
 
Func<MyData, dynamic> dataGrouping = md => new
    {
        md.Property1,
        md.Property2,
        md.Property3
    };

var groupedData = myDataCollection.GroupBy(dataGrouping);
 
While this will compile, it leaves me with no intellisense or strong typing inside the group as the type is dynamic.
 
I can't specify the type of dataGrouping as var, because I'm in C# and I get complaints of Cannot assign lambda expression to implicitly typed local variable.
 
Could I replace dynamic with the result of GetType() on the anonymous type? I'd then need the type before it's used in the lambda, but I can't see a useful way to get a handle on it before I'm already into the lambda itself.
 
Is there an elegant way of getting the type of this anonymous class?

原文：https://stackoverflow.com/questions/3446819