c# - 访问 C# 匿名类型对象

Question

我如何访问其声明范围之外的匿名类型的对象？

例如

void FuncB()
{
var obj = FuncA();
Console.WriteLine(obj.Name);
}

??? FuncA()
{
var a = (from e in DB.Entities
where e.Id == 1
select new {Id = e.Id, Name = e.Name}).FirstOrDefault();

return a;
}

Answer 1

正如其他答案所述，你真的不应该这样做。但是，如果你坚持，那么有一个被称为“以身作则”的讨厌的技巧可以让你做到这一点。该技术在几篇文章中有所提及，here和 here .

public void FuncB()
{
    var example = new { Id = 0, Name = string.Empty };

    var obj = CastByExample(FuncA(), example);
    Console.WriteLine(obj.Name);
}

private object FuncA()
{
    var a = from e in DB.Entities
            where e.Id == 1
            select new { Id = e.Id, Name = e.Name };

    return a.FirstOrDefault();
}

private T CastByExample<T>(object target, T example)
{
    return (T)target;
}

(虽然 the author of one of those articles says that he doesn't want to be associated with it either ，但我不能把这个黑客归功于此。他的名字可能很熟悉。)