C# 方法返回未知类型的列表

我有一个linq查询，它返回未知类型值的列表。我想将此查询包含在一个方法中，并使用该方法获取结果

public __________ getResult() {
var result = from ps in _context.PurchasingShipments
                     group ps by ps.date.Value.Year into grp
                     select new
                     {
                         Year = grp.Key,
                         Cost = grp.Sum(x => x.NoOfPieces * x.PricePerPiece + x.Micelleneous + x.TransportCost + x.SupplierCommission)
                     };

        return result;

}

---

上面是一个示例，getResult方法的返回类型应该是什么？请帮助

您只能返回对象，您应该创建一个类：

public class CostYearModel{
    public int Year {get; set;}
    public int Cost {get; set;}
}
public List<CostYearModel> getResult() {
    var result = from ps in _context.PurchasingShipments
                         group ps by ps.date.Value.Year into grp
                         select new CostYearModel
                         {
                             Year = grp.Key,
                             Cost = grp.Sum(x => x.NoOfPieces * x.PricePerPiece + x.Micelleneous + x.TransportCost + x.SupplierCommission)
                         };

      return result.ToList();
}

公共类成本模型{
公共整数年{get；set；}
公共整数成本{get；set；}
}
公共列表getResult（）{
var结果=来自_context.PurchasingShipments中的ps
按ps.date.Value.Year将ps分组到grp中
选择新模型
{
年份=grp.键，
成本=总成本（x=>x.NoOfPieces*x.单价+x.胶束+x.运输成本+x.供应商佣金）
};
返回result.ToList（）；
}

解决方案1:I强烈建议您创建一个包含属性的模型，并返回该模型的列表

public class CostYearModel {
     public int Year { get; set; }
     public int Cost { get; set; }
} 

方法如下所示

public List<CostYearModel> getResult() {
    var result = from ps in _context.PurchasingShipments
                 group ps by ps.date.Value.Year into grp
                 select new CostYearModel
                 {
                     Year = grp.Key,
                     Cost = grp.Sum(x => x.NoOfPieces * x.PricePerPiece + x.Micelleneous + x.TransportCost + x.SupplierCommission)
                 };

      return result.ToList();
}

---

您正在

select

语句中创建匿名类型，因此

result

将是匿名类型的可枚举项。返回该值的唯一方法是将其作为

IEnumerable

，但是如果这样做，您将如何在

getResult

方法之外使用它？您最好创建一个包含这两个字段的特定结果类型（类）。您可能需要将

CustomClass

更改为

CostYearModel

public List<Object> getResult() {
    var result = from ps in _context.PurchasingShipments
                 group ps by ps.date.Value.Year into grp
                 select (new
                 {
                    Year = grp.Key,
                    Cost = grp.Sum(x => x.NoOfPieces * x.PricePerPiece + x.Micelleneous + x.TransportCost + x.SupplierCommission)
                 } as Object);

    return result.ToList();
}

foreach (var costYear in result)
{
    var properties = costYear.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);
    foreach (var property in properties)
    {
        var value = property.GetValue(costYear, null);
    }
}