c# - C# IQueryable 在一个组 new 之后连接两个字段

Question

我有这个 IQueryable 从我的表中获取一些属性，但它有一个group new并且我想从那里连接两个字符串。

from comp in companies
join con in contacts on new { A = comp.Company_ID, B = comp.Location_ID } equals new { A = con.Company_ID, B = con.Location_ID } into comp_con
group new { comp, cc } by new
{
    comp.Company_ID,
    comp.Location_ID,
    comp.Company_Name,
    comp.City,
    comp.State,
    comp.Total_Fleet_Range,
    comp.Total_Locations
} into gcomp
select new MyObject
{
    ...,
    PropertyConcatenated = gcomp.Key.State + gcomp.Key.City // This is the part that doesn't work
};

当我尝试将其列为列表时，我得到了一个空引用异常，但城市和州都有值。

标签： c#linqiqueryable