LINQ如何連接2 db列以顯示在下拉列表中

Question

我試圖通過使用LINQ連接product_name和product_prize_kg，以便我可以在下拉列表中顯示它作爲一個字段。當我嘗試這樣做時，出現以下錯誤。

value of type 'system.collections.generic.list(of anonymous type)' cannot be converted to ...

我的代碼是這樣的：

Public Function selectAll() As List(Of tblProduct) 
    Dim result = From product In dc.tblProducts 
       Select New With 
       { 
        Key .productID = product.pk_product_id, 
        Key .productNameKg = Convert.ToString(product.product_name) & " " & Convert.ToString(product.product_price_kg) 
       } 

    Return result.ToList() 
End Function 

這是我想填補下拉列表。

<asp:DropDownList ID="DropDownList1" runat="server" 
     DataSourceID="ObjectDataSource1" DataTextField="productNameKg" 
     DataValueField="productID"> 
    </asp:DropDownList> 

感謝

Grtz Simke

Answer 1

Public Function selectAll() As List(Of Product) 
    Dim result = From product In tblProducts 
       Select New Product With 
      { 
       .ProductId = product.pk_product_id, 
       .ProductNameKg = Convert.ToString(product.product_name) & " " & Convert.ToString(product.product_price_kg) 
      } 


    Return result.ToList() 
End Function 



Public Class Product 

    Property ProductId As String 

    Property ProductNameKg As String 

End Class