將一個布爾值添加到'選擇新的'Linq查詢

Question

我試圖添加一個布爾值（InStock）到一個Linq查詢，其中它設置一個基於條件的值，但我得到一個錯誤：

The name 'Any' does not exist in the current context. Cannot resolve symbol 'Any1'。

不確定這裏的語法是什麼？

var query = from o in Orders 
      join i in OrderItems on o.SKU equals i.SKU 
      where o.OrderId == orderId 
      select new OrderObject 
      { 
       Id = o.OrderId, 
       WarehouseQty = i.AvailableQty, 
       Sku = i.Sku, 
       InStock = Any(x => x.AvailableQty > 0) //<--need to assign boolean here 

      }; 

Answer 1

If the AvailableQty is > 0, then set InStock to true

好，然後用

var query = from o in Orders 
      join i in OrderItems on o.SKU equals i.SKU 
      where o.OrderId == orderId 
      select new OrderObject 
      { 
       Id = o.OrderId, 
       WarehouseQty = i.AvailableQty, 
       Sku = i.Sku, 
       InStock = i.AvailableQty > 0 
      }; 

無需使用Enumerable.Any這是用來搜索其他收藏品。

Answer 2

你可能想使用InStock = i.AvailableQty > 0，像這樣：

var query = from o in Orders 
      join i in OrderItems on o.SKU equals i.SKU 
      where o.OrderId == orderId 
      select new OrderObject 
      { 
       Id = o.OrderId, 
       WarehouseQty = i.AvailableQty, 
       Sku = i.Sku, 
       InStock = i.AvailableQty > 0 
      }; 

但是，它似乎是多餘的具有這種和的WarehouseQty財產。爲什麼不只是添加一個只讀的屬性到你的班級：

public class OrderObject 
{ 
    //snip 

    public bool InStock => WarehouseQty > 0; 
}