我有一个名为Order的类,它具有OrderId、OrderDate、Quantity和Total等财产。我有这个订单类的列表:
List<Order> objListOrder = new List<Order>();
GetOrderList(objListOrder); // fill list of orders
我想根据Order对象的一个属性对列表进行排序;例如通过订单日期或订单id。
如何在C#中执行此操作?
我有一个名为Order的类,它具有OrderId、OrderDate、Quantity和Total等财产。我有这个订单类的列表:
List<Order> objListOrder = new List<Order>();
GetOrderList(objListOrder); // fill list of orders
我想根据Order对象的一个属性对列表进行排序;例如通过订单日期或订单id。
如何在C#中执行此操作?
当前回答
如果需要对Question实体中的字符串Id进行排序使用Sort函数和委托在解析Id后对Id进行排序价值
class Question
{
public List<QuestionInfo> Questions Info{ get; set; }
}
class QuestionInfo
{
public string Id{ get; set; }
public string Questions{ get; set; }
}
var questionnaire = new Question();
questionnaire.QuestionInfo.Sort((x, y) => int.Parse(x.Id, CultureInfo.CurrentCulture) - int.Parse(y.Id, CultureInfo.CurrentCulture));
其他回答
假设您有以下代码,在这段代码中,我们有一个Passenger类,其中有几个我们想要排序的财产。
public class Passenger
{
public string Name { get; }
public string LastName { get; }
public string PassportNo { get; }
public string Nationality { get; }
public Passenger(string name, string lastName, string passportNo, string nationality)
{
this.Name = name;
this.LastName = lastName;
this.PassportNo = passportNo;
this.Nationality = nationality;
}
public static int CompareByName(Passenger passenger1, Passenger passenger2)
{
return String.Compare(passenger1.Name, passenger2.Name);
}
public static int CompareByLastName(Passenger passenger1, Passenger passenger2)
{
return String.Compare(passenger1.LastName, passenger2.LastName);
}
public static int CompareNationality(Passenger passenger1, Passenger passenger2)
{
return String.Compare(passenger1.Nationality, passenger2.Nationality);
}
}
public class TestPassengerSort
{
Passenger p1 = new Passenger("Johon", "Floid", "A123456789", "USA");
Passenger p2 = new Passenger("Jo", "Sina", "A987463215", "UAE");
Passenger p3 = new Passenger("Ped", "Zoola", "A987855215", "Italy");
public void SortThem()
{
Passenger[] passengers = new Passenger[] { p1, p2, p3 };
List<Passenger> passengerList = new List<Passenger> { p1, p2, p3 };
Array.Sort(passengers, Passenger.CompareByName);
Array.Sort(passengers, Passenger.CompareByLastName);
Array.Sort(passengers, Passenger.CompareNationality);
passengerList.Sort(Passenger.CompareByName);
passengerList.Sort(Passenger.CompareByLastName);
passengerList.Sort(Passenger.CompareNationality);
}
}
因此,您可以使用Composition委托实现排序结构。
请让我用@LukeH的一些示例代码来完成答案,因为我已经测试了它,我相信它可能对某些人有用:
public class Order
{
public string OrderId { get; set; }
public DateTime OrderDate { get; set; }
public int Quantity { get; set; }
public int Total { get; set; }
public Order(string orderId, DateTime orderDate, int quantity, int total)
{
OrderId = orderId;
OrderDate = orderDate;
Quantity = quantity;
Total = total;
}
}
public void SampleDataAndTest()
{
List<Order> objListOrder = new List<Order>();
objListOrder.Add(new Order("tu me paulo ", Convert.ToDateTime("01/06/2016"), 1, 44));
objListOrder.Add(new Order("ante laudabas", Convert.ToDateTime("02/05/2016"), 2, 55));
objListOrder.Add(new Order("ad ordinem ", Convert.ToDateTime("03/04/2016"), 5, 66));
objListOrder.Add(new Order("collocationem ", Convert.ToDateTime("04/03/2016"), 9, 77));
objListOrder.Add(new Order("que rerum ac ", Convert.ToDateTime("05/02/2016"), 10, 65));
objListOrder.Add(new Order("locorum ; cuius", Convert.ToDateTime("06/01/2016"), 1, 343));
Console.WriteLine("Sort the list by date ascending:");
objListOrder.Sort((x, y) => x.OrderDate.CompareTo(y.OrderDate));
foreach (Order o in objListOrder)
Console.WriteLine("OrderId = " + o.OrderId + " OrderDate = " + o.OrderDate.ToString() + " Quantity = " + o.Quantity + " Total = " + o.Total);
Console.WriteLine("Sort the list by date descending:");
objListOrder.Sort((x, y) => y.OrderDate.CompareTo(x.OrderDate));
foreach (Order o in objListOrder)
Console.WriteLine("OrderId = " + o.OrderId + " OrderDate = " + o.OrderDate.ToString() + " Quantity = " + o.Quantity + " Total = " + o.Total);
Console.WriteLine("Sort the list by OrderId ascending:");
objListOrder.Sort((x, y) => x.OrderId.CompareTo(y.OrderId));
foreach (Order o in objListOrder)
Console.WriteLine("OrderId = " + o.OrderId + " OrderDate = " + o.OrderDate.ToString() + " Quantity = " + o.Quantity + " Total = " + o.Total);
//etc ...
}
下面是一个通用LINQ扩展方法,它不会创建列表的额外副本:
public static void Sort<T,U>(this List<T> list, Func<T, U> expression)
where U : IComparable<U>
{
list.Sort((x, y) => expression.Invoke(x).CompareTo(expression.Invoke(y)));
}
要使用它:
myList.Sort(x=> x.myProperty);
我最近构建了另一个接受ICompare<U>的插件,以便您可以自定义比较。当我需要进行自然字符串排序时,这很有用:
public static void Sort<T, U>(this List<T> list, Func<T, U> expression, IComparer<U> comparer)
where U : IComparable<U>
{
list.Sort((x, y) => comparer.Compare(expression.Invoke(x), expression.Invoke(y)));
}
如果需要对列表进行排序,则可以使用sort方法,传递Comparison<T>委托:
objListOrder.Sort((x, y) => x.OrderDate.CompareTo(y.OrderDate));
如果您希望创建一个新的排序序列而不是就地排序,那么可以使用LINQ的OrderBy方法,如其他答案中所述。
我能想到的最简单的方法是使用Linq:
List<Order> SortedList = objListOrder.OrderBy(o=>o.OrderDate).ToList();