如何在asp.net mvc中使用字符串变量作为列名

Question

我不确定这样的事情是否可能。但我想使用一个变量作为列名。

下面是我必须使用的代码

cartall.CartItems = cartdatas.Select(a => new Models.DTO.CartDTO.CartVM()
{
    VariationId = a.VariationId,
    ColorName = a.ColorName,
    StockInfo = rpstock.FirstOrDefault(x => x.Id == a.VariationId).Yellow
}).ToList();

但我想像下面这样使用它。

我要使用的代码：

cartall.CartItems = cartdatas.Select(a => new Models.DTO.CartDTO.CartVM()
{
    VariationId = a.VariationId,
    ColorName = a.ColorName,
    StockInfo = rpstock.FirstOrDefault(x => x.Id == a.VariationId).(a.ColorName)
}).ToList();

我的 Stock.cs

public class Stock:Base.BaseEntity
{
    public int Id { get; set; }
    public int? Yellow { get; set; }
    public int? Red { get; set; }
    public int? White { get; set; }

    public virtual VariationEntity.Variation Variation { get; set; }
}

我的 Variation.cs

public class Variation : Base.BaseEntity
{
    public int Id { get; set; }
    public int OwnerProductID { get; set; }
    public string SKU { get; set; }
    public short? Height { get; set; }
    public short? Width { get; set; }
    public decimal? Price { get; set; }
    public string Delivery { get; set; }
    public int? OrderLimit { get; set; }

    public virtual StockEntity.Stock Stock { get; set; }
}

stock.cs 和variation.cs 之间存在一对一的关系

Answer 1

这应该可行：

 StockInfo = rpstock.FirstOrDefault(x => x.Id == a.VariationId && x.ColorName == a.ColorName)

Answer 2

我创建了一个Method，它将采用list 和一个Column Name，然后返回该列的value。请检查这个。

代码：

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public class Stock
    {
        public int Id { get; set; }
        public int? Yellow { get; set; }
        public int? Red { get; set; }
        public int? White { get; set; }
    }

    public static void Main()
    {
        List<Stock> list = new List<Stock>();
        list.Add(new Stock(){Id=1, Yellow = 50, Red = 0, White = 205});
        list.Add(new Stock(){Id=2, Yellow = 20, Red = 200, White = 35});
        list.Add(new Stock(){Id=3, Yellow = 0, Red = 100, White = 155});

        string ColumnName = "Yellow";

        var Test1 = GetColumnValue(list.Where(m=>m.Id == 1).ToList(), ColumnName);
        var Test2 = GetColumnValue(list.Where(m=>m.Id == 2).ToList(), ColumnName);
        var Test3 = GetColumnValue(list.Where(m=>m.Id == 3).ToList(), ColumnName);

        Console.WriteLine(Test1);
        Console.WriteLine(Test2);
        Console.WriteLine(Test3);
    }

    public static object GetColumnValue(List<Stock> items, string columnName)
    {
        var values = items.Select(x => x.GetType().GetProperty(columnName).GetValue(x)).FirstOrDefault();
        return values;
    }
}

您必须在代码中使用GetColumnValue 方法，如下所示：

cartall.CartItems = cartdatas.Select(a => new Models.DTO.CartDTO.CartVM()
{
    VariationId = a.VariationId,
    ColorName = a.ColorName,
    StockInfo = GetColumnValue(rpstock.FirstOrDefault(x => x.Id == a.VariationId).ToList(), a.ColorName)
}).ToList();

您可以在DotNetFiddle 中运行此解决方案。