C#Linq，对象定义不包含属性 [英] C# Linq, object definition does not contains a property

问题描述

我需要您的帮助

我刚刚编写了以下代码

var anynomousObject = new { Amount = 10, weight = 20 };

List<object> ListOfAnynomous = new List<object> { anynomousObject };
var productQuery =
            from prod in ListOfAnynomous
            select new { prod.Amount, prod.weight }; // here it object on 'prod.Amount, prod.weight' that the object defenetion does not contains the "Amount" and "weight" properties

 foreach (var v in productQuery)
  {
    Console.WriteLine(v.Amount, v.weight);
  }

所以请您帮我解决这个问题.

so please could you help me to solve this problem.

推荐答案

您需要创建对象定义的类，或者使用动态键盘而不是在对象中装箱:

You need to make a class of your object definition, or using the dynamic keywork instead of boxing in object :

 var anynomousObject = new { Amount = 10, weight = 20 };

 List<dynamic> ListOfAnynomous = new List<dynamic> { anynomousObject };
 var productQuery =
                    from prod in ListOfAnynomous
                    select new { prod.Amount, prod.weight }; 

 foreach (var v in productQuery)
 {
    Console.WriteLine(v.Amount, v.weight);
 }

这是因为，当您将其装箱为对象时，编译器不知道匿名var的定义. Dynamic使它在运行时而不是在编译时求值.

this is because, when you box as object, the compiler doesn't know the definition of your anonymous var. Dynamic make it evaluate at runtime instead of compile-time.

另一种选择是创建一个类或结构.

The other option is to create a class or struct.

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