C# 匿名类型成员声明符无效
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Invalid anonymous type member declarator
提问by chhenning
I have a problem with the following code which should work, according to this MSDN Forums post.
根据这篇 MSDN 论坛帖子，我对以下应该工作的代码有问题。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
namespace LINQTest
{
class Program
{
class Schedule
{
public int empid { get; set; }
public int hours { get; set; }
public DateTime date { get; set; }
public DateTime weekending { get; set; }
}
static void Main(string[] args)
{
List<Schedule> Schedules = new List<Schedule>();
var bla = from s in Schedules
group s by new { s.empid, s.weekending} into g
select new { g.Key.empid, g.Key.weekending, g.Sum(s=>s.hours)};
}
}
}
I'm getting the error with the sum function: Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or member access.
我收到 sum 函数的错误：无效的匿名类型成员声明符。匿名类型成员必须使用成员赋值、简单名称或成员访问进行声明。
What's wrong?
怎么了？
采纳答案by MarcinJuraszek
You have to name the property used to store Summethod result:
您必须命名用于存储Sum方法结果的属性：
select new { g.Key.empid, g.Key.weekending, Sum = g.Sum(s=>s.hours)};
Compiler can't infer the property name when you're assigning the value from expression:
当您从表达式分配值时，编译器无法推断属性名称：
Anonymous Types (C# Programming Guide)
You must provide a name for a property that is being initialized with an expression (...)
您必须为正在使用表达式 (...) 初始化的属性提供名称
