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C# 空格并选择具有排序而不是列表的类

c# generics list sorting

C# 空格并选择具有排序而不是列表的类,c#,generics,list,sorting,C#,Generics,List,Sorting,并尽可能避免使用反射的通用实现，这也会导致性能问题。经典的面向对象解决方案 首先，我必须屈服于林克的威严。。。。现在我们已经解决了这个问题 Jimmyhoff答案的变体。对于泛型，CompareTo参数变为类型安全 public class Order : IComparable<Order> { public int CompareTo( Order that ) { if ( that == null ) return 1; if ( t

并尽可能避免使用反射的通用实现，这也会导致性能问题。

经典的面向对象解决方案

首先，我必须屈服于林克的威严。。。。现在我们已经解决了这个问题

Jimmyhoff答案的变体。对于泛型，
CompareTo
参数变为类型安全

public class Order : IComparable<Order> {

    public int CompareTo( Order that ) {
        if ( that == null ) return 1;
        if ( this.OrderDate > that.OrderDate) return 1;
        if ( this.OrderDate < that.OrderDate) return -1;
        return 0;
    }
}

// in the client code
// assume myOrders is a populated List<Order>
myOrders.Sort(); 

公共类顺序：i可比较{
公共int比较（订购）{
如果（that==null）返回1；
如果（this.OrderDate>that.OrderDate）返回1；
if（this.OrderDate
当然，这个默认的可排序性是可重用的。也就是说，每个客户机不必冗余地重新写入排序逻辑。交换“1”和“-1”（或逻辑运算符，由您选择）可反转排序顺序。

基于GenericTypeTea的比较器：
通过添加排序标志，我们可以获得更大的灵活性：

public class MyOrderingClass : IComparer<Order> {  
    public int Compare(Order x, Order y) {  
        int compareDate = x.Date.CompareTo(y.Date);  
        if (compareDate == 0) {  
            int compareOrderId = x.OrderID.CompareTo(y.OrderID);  

            if (OrderIdDescending) {  
                compareOrderId = -compareOrderId;  
            }  
            return compareOrderId;  
        }  

        if (DateDescending) {  
            compareDate = -compareDate;  
        }  
        return compareDate;  
    }  

    public bool DateDescending { get; set; }  
    public bool OrderIdDescending { get; set; }  
}
对于属性选择，您可以做一些更一般的事情，但对于您选择的类型，您可以做一些具体的事情，例如“顺序”：

将函数编写为通用函数：

public List<Order> GetOrderList<T>(IEnumerable<Order> orders, Func<Order, T> propertySelector)
        {
            return (from order in orders
                    orderby propertySelector(order)
                    select order).ToList();
        }
您可以更通用，并为您想要订购的产品定义开放式类型：

public List<T> OrderBy<T,P>(IEnumerable<T> collection, Func<T,P> propertySelector)
        {
            return (from item in collection
                    orderby propertySelector(item)
                    select item).ToList();
        }
这是一种愚蠢的、不必要的、复杂的方式来执行LINQ风格的“OrderBy”，
但它可能会给你一个如何以通用方式实现它的线索

请让我用一些示例代码完成@LukeH的回答，因为我已经测试了它。我相信它可能对一些人有用：

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 ...
}

公共类秩序
{
公共字符串OrderId{get；set；}
public DateTime OrderDate{get；set；}
公共整数数量{get；set；}
公共整数总计{get；set；}
公共订单（字符串orderId、日期时间orderDate、整数数量、整数总数）
{
OrderId=OrderId；
OrderDate=OrderDate；
数量=数量；
总计=总计；
}
}
public void SampleDataAndTest（）
{
List objListOrder=新列表（）；
新增（新订单（“tu me paulo”，转换为截至日期（“01/06/2016”），1，44）；
objListOrder.Add（新订单（“ante laudabas”，转换为当前日期（“02/05/2016”），2，55）；
objListOrder.Add（新订单（“ad ordinem”，Convert.ToDateTime（“03/04/2016”），5，66）；
objListOrder.Add（新订单（“配置”，转换为ToDateTime（“04/03/2016”），9，77）；
objListOrder.Add（新订单（“que rerum ac”，转换为截至日期（“05/02/2016”），10，65）；
新增订单（新订单（“locorum；cuius”，转换为截止日期（“2016年1月6日”），1343）；
WriteLine（“按日期升序对列表排序：”；
objListOrder.Sort（（x，y）=>x.OrderDate.CompareTo（y.OrderDate））；
foreach（objListOrder中的订单o）
Console.WriteLine（“OrderId=“+o.OrderId+”OrderDate=“+o.OrderDate.ToString（）+”Quantity=“+o.Quantity+”Total=“+o.Total”）；
WriteLine（“按日期降序对列表排序：”；
objListOrder.Sort（（x，y）=>y.OrderDate.CompareTo（x.OrderDate））；
foreach（objListOrder中的订单o）
Console.WriteLine（“OrderId=“+o.OrderId+”OrderDate=“+o.OrderDate.ToString（）+”Quantity=“+o.Quantity+”Total=“+o.Total”）；
WriteLine（“按OrderId升序对列表排序：”；
objListOrder.Sort（（x，y）=>x.OrderId.CompareTo（y.OrderId））；
foreach（objListOrder中的订单o）
Console.WriteLine（“OrderId=“+o.OrderId+”OrderDate=“+o.OrderDate.ToString（）+”Quantity=“+o.Quantity+”Total=“+o.Total”）；
//等等。。。
}
以上所有答案对我来说都不够笼统，所以我做了这个：

var someUserInputStringValue = "propertyNameOfObject i.e. 'Quantity' or 'Date'";
var SortedData = DataToBeSorted
                   .OrderBy(m => m.GetType()
                                  .GetProperties()
                                  .First(n => 
                                      n.Name == someUserInputStringValue)
                   .GetValue(m, null))
                 .ToList();
但要小心海量数据集。这是一个简单的代码，但如果集合很大，并且集合的对象类型有大量字段，则可能会给您带来麻烦。 运行时为NxM，其中：

N=集合中元素的数量

M=#在对象中的属性中

任何使用可空类型的人，
值
必须使用
比较

objListOrder.Sort（（x，y）=>x.YourNullableType.Value.CompareTo（y.YourNullableType.Value））
假设您有以下代码，在这段代码中，我们有一个乘客类，它有两个属性，我们希望根据这些属性进行排序


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);

    }
}



公共舱乘客
{
公共字符串名称{get；}
公共字符串LastName{get；}
公共字符串PassportNo{get；}
公共字符串{get；}
公共乘客（字符串名称、字符串姓氏、字符串护照号、字符串国籍）
{
this.Name=Name；
this.LastName=LastName；
this.PassportNo=护照号；
这.国籍=国籍；
}
公共静态int比较码名称（乘客1、乘客2）
{
返回String.Compare（passenger1.Name，passenger2.Name）；
}
公共静态int CompareByLastName（乘客1、乘客2）
{
返回String.Compare（passenger1.LastName，passenger2.LastName）；
}
公共静态国际比较（乘客1、乘客2）
{
返回字符串.Compare（passenger1.national，passenger2.national）；
}
}
公共类TestPassengerSort
{
乘客p1=新乘客（“约翰”、“弗洛伊德”、“A123456789”、“美国”）；
乘客p2=新乘客（“Jo”、“新浪”、“A987463215”、“阿联酋”）；
乘客p3=新乘客（“Ped”、“Zoola”、“A987855215”、“意大利”）；
公共无效SortThem（）
{
乘客[]乘客=新乘客[]{p1、p2、p3}；
List passengerList=新列表{p1，p2，p3}；
数组.Sort（乘客，乘客.CompareByName）；
数组.Sort（乘客，乘客.CompareByLastName）；
数组.排序（乘客，乘客.比较性）；
passengerList.Sort（passer.CompareByName）；
passengerList.Sort（Passenger.CompareByLa

  List<Order> objListOrder = 
    source.OrderBy(order => order.OrderDate).ThenBy(order => order.OrderId).ToList();



List<Order> objListOrder = GetOrderList();
objListOrder.Sort(
    delegate(Order p1, Order p2)
    {
        return p1.OrderDate.CompareTo(p2.OrderDate);
    }
);



orderList.Sort(
    delegate(Order p1, Order p2)
    {
        int compareDate = p1.Date.CompareTo(p2.Date);
        if (compareDate == 0)
        {
            return p2.OrderID.CompareTo(p1.OrderID);
        }
        return compareDate;
    }
);



public class MyOrderingClass : IComparer<Order>
{
    public int Compare(Order x, Order y)
    {
        int compareDate = x.Date.CompareTo(y.Date);
        if (compareDate == 0)
        {
            return x.OrderID.CompareTo(y.OrderID);
        }
        return compareDate;
    }
}



IComparer<Order> comparer = new MyOrderingClass();
orderList.Sort(comparer);



public class Order : IComparable
{
    public DateTime OrderDate { get; set; }
    public int OrderId { get; set; }

    public int CompareTo(object obj)
    {
        Order orderToCompare = obj as Order;
        if (orderToCompare.OrderDate < OrderDate || orderToCompare.OrderId < OrderId)
        {
            return 1;
        }
        if (orderToCompare.OrderDate > OrderDate || orderToCompare.OrderId > OrderId)
        {
            return -1;
        }

        // The orders are equivalent.
        return 0;
    }
}



//Get data from database, then sort list by staff name:

List<StaffMember> staffList = staffHandler.GetStaffMembers();

var sortedList = from staffmember in staffList
                 orderby staffmember.Name ascending
                 select staffmember;



public List<T> Sort_List<T>(string sortDirection, string sortExpression, List<T> data)
    {

        List<T> data_sorted = new List<T>();

        if (sortDirection == "Ascending")
        {
            data_sorted = (from n in data
                              orderby GetDynamicSortProperty(n, sortExpression) ascending
                              select n).ToList();
        }
        else if (sortDirection == "Descending")
        {
            data_sorted = (from n in data
                              orderby GetDynamicSortProperty(n, sortExpression) descending
                              select n).ToList();

        }

        return data_sorted;

    }

    public object GetDynamicSortProperty(object item, string propName)
    {
        //Use reflection to get order type
        return item.GetType().GetProperty(propName).GetValue(item, null);
    }



public object GetDynamicSortProperty(object item, string propName)
    {
        try
        {                 
            string[] prop = propName.Split('.'); 

            //Use reflection to get order type                   
            int i = 0;                    
            while (i < prop.Count())
            {
                item = item.GetType().GetProperty(prop[i]).GetValue(item, null);
                i++;
            }                     

            return item;
        }
        catch (Exception ex)
        {
            throw ex;
        }


    } 



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)));
}



myList.Sort(x=> x.myProperty);



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)));
}



public class Order : IComparable<Order> {

    public int CompareTo( Order that ) {
        if ( that == null ) return 1;
        if ( this.OrderDate > that.OrderDate) return 1;
        if ( this.OrderDate < that.OrderDate) return -1;
        return 0;
    }
}

// in the client code
// assume myOrders is a populated List<Order>
myOrders.Sort(); 



public class MyOrderingClass : IComparer<Order> {  
    public int Compare(Order x, Order y) {  
        int compareDate = x.Date.CompareTo(y.Date);  
        if (compareDate == 0) {  
            int compareOrderId = x.OrderID.CompareTo(y.OrderID);  

            if (OrderIdDescending) {  
                compareOrderId = -compareOrderId;  
            }  
            return compareOrderId;  
        }  

        if (DateDescending) {  
            compareDate = -compareDate;  
        }  
        return compareDate;  
    }  

    public bool DateDescending { get; set; }  
    public bool OrderIdDescending { get; set; }  
}  



MyOrderingClass comparer = new MyOrderingClass();  
comparer.DateDescending = ...;  
comparer.OrderIdDescending = ...;  
orderList.Sort(comparer);  



public List<Order> GetOrderList<T>(IEnumerable<Order> orders, Func<Order, T> propertySelector)
        {
            return (from order in orders
                    orderby propertySelector(order)
                    select order).ToList();
        } 



var ordersOrderedByDate = GetOrderList(orders, x => x.OrderDate);



public List<T> OrderBy<T,P>(IEnumerable<T> collection, Func<T,P> propertySelector)
        {
            return (from item in collection
                    orderby propertySelector(item)
                    select item).ToList();
        } 



var ordersOrderedByDate = OrderBy(orders, x => x.OrderDate);



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 ...
}



var someUserInputStringValue = "propertyNameOfObject i.e. 'Quantity' or 'Date'";
var SortedData = DataToBeSorted
                   .OrderBy(m => m.GetType()
                                  .GetProperties()
                                  .First(n => 
                                      n.Name == someUserInputStringValue)
                   .GetValue(m, null))
                 .ToList();



var obj = db.Items.Where...

var orderBYItemId = obj.OrderByDescending(c => Convert.ToInt32(c.ID));



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);

    }
}



 public class OrderingAscending : IComparer<String>
    {
        public int Compare(String x, String y)
        {
            Int32.TryParse(x, out var xtmp);
            Int32.TryParse(y, out var ytmp);

            int comparedItem = xtmp.CompareTo(ytmp);
            return comparedItem;
        }
    }



 IComparer<String> comparerHandle = new OrderingAscending();
 yourList.Sort(comparerHandle);



    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));