在VB.net

Question

使用LINQ搜索對象的列表中的對象名單上有2班

Public Class Shipper 

    Public Property ShipperID As Long 
    Public Property CreateDate As DateTime 
    Public Property ShipperCode As String 
    Public Property ShipperName As String 
    Public Property ShippingMethods As List(Of ShippingMethod) 

Public Class ShippingMethod 

    Public Property ShippingMethodID As Long 
    Public Property ShipperID As Long 
    Public Property CreateDate As DateTime 
    Public Property ShipppingMethod As String 
    Public Property ShipppingMethodCode As String 

我試圖尋找貨主的列表，其中shippercode是空白，ShipperName不是空白的 - 我得到的通過

Dim oListShipper As List(Of Shipper) = GetAllShippers() 
Dim oListShipperRet As List(Of Shipper) = _ 
     oListShipper.FindAll(Function(c) (c.ShipperCode = "" And _ 
              c.ShipperName <> "")) 

現在我該怎樣讓所有的貨主那裏ShippingMethod.ShipppingMethodCode = '' 和ShippingMethod.ShipppingMethod <>'

我試過

oListShipper.FindAll(Function(c) (c.ShipperCode = "" And _ 
            c.ShipperName <> "")) Or _ 
(c.ShippingMethods.FindAll(Function(d) d.ShipppingMethodCode = "" And _ 
             d.ShipppingMethod <> "").Count > 1))) 

但沒有工作。任何想法 ？

感謝 Jothish

Answer 1

相信的FindAll方法是直接連接到List類，而不是真正的LINQ的一部分。嘗試使用Where和Any方法。我的VB技能是生鏽的，但我認爲它會是這樣的：

Dim oListShipper As List(Of Shipper) = GetAllShippers() 
Dim oListShipperRet As List(Of Shipper) = oListShipper 
    .Where(Function(c) (c.ShipperCode = "" And c.ShipperName <> "") 
     OR (c.ShippingMethods.Any(
      Function(d) d.ShipppingMethodCode = "" And d.ShipppingMethod <> "") 
    )) 
    .ToList();