如何汇总Linq查询中的字符串列表？

我需要最终使我的MVC表中的列有一串OrderNumbers。我似乎无法找出已经拥有的如何汇总Linq查询中的字符串列表？

public IEnumerable<OrderShippedListModel> GetRecentShippedOrders(string authenticatedUsername) 
{ 
    User currentUser = new User().GetUser(authenticatedUsername); 
    Order (from r in dc.Orders 
      where r.Location.OrganizationID == currentUser.OrganizationID 
      && r.CloseDate != null 
      && r.ProductShipDate != null 
      orderby r.LastModifiedDate descending 
      select new OrderShippedListModel 
      { 
       ID = r.ID, 
       OrderNumbers = r.Processes.Select(p=>p.OrderNumber), //This needs to aggregate to a string 
       Label = r.Label, 
       Location = r.Location.Label, 
       CreateDate = r.CreateDate, 
       ProductShipDate = r.ProductShipDate, 
       LastModifiedDate = r.LastModifiedDate, 
       CloseDate = r.CloseDate 
      }).Take(3); 
}

集合这里是我的类模型

public class OrderShippedListModel 
{ 
    public int ID { get; set; } 

    public string Label { get; set; } 

    public string Location { get; set; } 

    [Display(Name = "Create Date")] 
    public DateTime CreateDate { get; set; } 

    [Display(Name = "Last Modified Date")] 
    public DateTime LastModifiedDate { get; set; } 

    [Display(Name = "Product Ship Date")] 
    public DateTime? ProductShipDate { get; set; } 

    [Display(Name = "Close Date")] 
    public DateTime? CloseDate { get; set; } 

    [Display(Name = "Job Numbers")] 
    public string OrderNumbers { get; set; } 
}

来源

2014-02-22 EdenMachine

使用string.Join：

OrderNumbers = string.Join("", r.Processes.Select(p=>p.OrderNumber)),

来源

2014-02-22 15:14:17 Alberto

另一个是汇总：

var s = r.Processes.Aggregate((accum, elem) => accum += elem.OrderNumber)

来源

2014-02-22 15:18:12 Paul

这效率显着降低因为它会导致创建大量的中间字符串，因此会花费大量的时间分配新的字符缓冲区，并在缓冲区之间一遍又一遍地复制相同的数据。 – Servy

我不知道这是效率低下，谢谢你指出这一点。 – Paul

如何汇总Linq查询中的字符串列表？

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