LINQ的問題查詢數據

Question

這裏的兩個集合是我一起工作的代碼：

 Collection<WorkOrderLabor> workOrder = new Collection<WorkOrderLabor>(); 
     Collection<ServiceItem> serviceItems = new Collection<ServiceItem>(); 

     serviceItems = from si in serviceItems 
         join cw in workOrder on si.ServiceKey equals cw.Key 
         select new { si }; 

     foreach (ServiceItem item in serviceItems) 
      ctrl.Items.Add(...); 

我收到此錯誤：

Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<AnonymousType#1>' to 'System.Collections.ObjectModel.Collection<ServiceItem>' 

我相信這是希望一個簡單的辦法，但我無法弄清楚。這背後的邏輯是我需要根據傳遞給此方法的鍵來查找工作訂單，然後獲取工單所有的服務項目並遍歷它們以將它們放入組合框中。

Answer 1

應該只是

Collection<WorkOrderLabor> workOrder = new Collection<WorkOrderLabor>(); 
Collection<ServiceItem> serviceItems = new Collection<ServiceItem>(); 

var filteredItems = from si in serviceItems 
        join cw in workOrder on si.ServiceKey equals cw.Key 
        select si; 

foreach (ServiceItem item in filteredItems) 
    ctrl.Items.Add(...); 

你不想返回匿名類型從LINQ表達的IEnumerable<>而是一個IEnumerable<ServiceItem>