如何從C＃列表中的記錄中僅獲取一個值？

Question

我有兩個自定義列表：

List<Detailsofemployee> empDetails = new List<Detailsofemployee>();
List<regionDetails> regDetails = new List<regionDetails>();

• empDetails值為{"1","Sam","IT"} 。
• regDetails值為{"IT","UK"} 。

我想從第一個列表中獲取數據，並據此從另一個列表中獲取數據

var det = (from l in empDetails where l.ID == "1" select l.Department)
var region = (from l in regDetails where l.Department == det select l.Country)

如何獲得det = "IT" ？

Answer 1

帶有檢查和用戶輸入值

using System.Linq;

var userInputId = //user input value
var emp = empDetails.FirstOrDefault(x => x.Id == userInputId);
var regDetail = new regionDetails();
if (emp != null)
{
   regDetail =  regDetails.FirstOrDefault(c => c.Department == emp.Department);
}
if (regDetail != null)
{
    return regDetail.Country;
}