在 C# 中将随机元素添加到通用列表答案

【问题标题】：Adding Random Element to GenericList in C#在 C# 中将随机元素添加到通用列表
【发布时间】：2021-12-29 18:30:49
【问题描述】：

我正在尝试使用数据结构制作一个简单的送餐系统。我在 ArrayList 中保存了 Neighborhood 名称，并在 GenericList 中保存了 Delivery Count、Food Name 和它的计数。我画了原理图并附上了照片。

我编写了打印“Hood Name and it's delivery count”的程序，我的代码和输出在这里：

using System;
using System.Collections;
using System.Collections.Generic;

namespace temp

{
    
    internal class delivery
    {
        public string food;
        public int count;

    }
    internal class Hood
    {
        public string Name;
        public int Number;
    }
    class programm
    {
        static void Main(string[] args)
        
        {

            string[] HoodName = { "Cherryhood", "NewCastle", "Greenlight", "Summerlin", "Westcity", "Paradise", "Legions", "Flamingos" };
            int[] TeslimatSayisi = { 4, 2, 7, 2, 7, 3, 0, 1 };
            ArrayList arrayList = new ArrayList();
            int counter = 0;
            List<Hood> genericList;
            Hood ClassExample;

            for (int i = 0; i < HoodName.Length;)
            {
                genericList = new List<Hood>();
                int elementCount = (int)Math.Pow(2, counter);
                for (int j = 0; j < elementCount; j++)
                {
                    ClassExample = new Hood();
                    ClassExample.Name = HoodName[i];
                    ClassExample.Number = TeslimatSayisi[i];
                    genericList.Add(ClassExample);
                    i++;
                    if (i == HoodName.Length) break;
                }
                arrayList.Add(genericList);
                counter++;
            }
            int counter2 = 0;
            foreach (List<Hood> temp in arrayList)
            {
                foreach (Hood temp2 in temp)
                    Console.WriteLine("Hood: " + temp2.Name +" | "+" Delivery Count: " + temp2.Number);
            }

我的输出是：

Hood: Cherryhood |  Delivery Count: 4
Hood: NewCastle |  Delivery Count: 2
Hood: Greenlight |  Delivery Count: 7
Hood: Summerlin |  Delivery Count: 2
Hood: Westcity |  Delivery Count: 7
Hood: Paradise |  Delivery Count: 3
Hood: Legions |  Delivery Count: 0
Hood: Flamingos |  Delivery Count: 1

我怎样才能得到这样的输出：

Hood: Cherryhood |  Delivery Count: 4 | Food's, count: Salat:2, Taco:5, Pizza:1, Burger:2
Hood: NewCastle |  Delivery Count: 2 | Food's, count: Pasta:15, Cake,7 
Hood: Greenlight |  Delivery Count: 7 | Food's, count: ................
Hood: Summerlin |  Delivery Count: 2 | ..........
Hood: Westcity |  Delivery Count: 7 |...........
Hood: Paradise |  Delivery Count: 3 |.................
Hood: Legions |  Delivery Count: 0 |...........
Hood: Flamingos |  Delivery Count: 1 |.....................

我猜我必须像这样制作食物清单和计数清单：

foods = {pizza, taco, burger, salad, pasta, cake..........}
count = {1, 5, 2, 2, 15 ,7...........}

我需要创建配送类（包含膳食名称、数量字段）。然后我必须用相关邻域中的 Delivery 对象的数量填充 ArrayList 中的每个通用列表。我可以创建一个食物列表并从中随机选择食物信息。对于这个项目，我们可以假设每次交付只能包含一种餐食（包括多少）。

我是 C# 和数据结构的新手，非常感谢您的帮助。

【问题讨论】：

标签： c# for-loop arraylist data-structures generic-list

【解决方案1】：

我会使用Lists 的对象来定义您的数据结构。然后用LINQ进行查询、操作等。我认为它会更灵活，让你更接近你想要的。像这样的：

using System;
using System.Collections.Generic;
using System.Linq;
                    
public class Program
{
    public static void Main()
    {
        var status = new List<Neighbourhood>{
            new Neighbourhood{
                Name = "Cherryhood",
                Id = 1,
                Orders = new List<Order>{
                    new Order{
                        Id = 300,
                        OrderItems = new List<string>{
                            "Salad",
                            "Taco",
                            "Pizza"
                        }
                    },
                    new Order{
                        Id = 301,
                        OrderItems = new List<string>{
                            "Cake",
                            "Taco",
                            "Pasta",
                            "Burger"
                        }
                    },
                    new Order{
                        Id = 302,
                        OrderItems = new List<string>{
                            "Salad",
                            "Pasta"
                        }
                    }
                }
            },
            new Neighbourhood{
                Name = "Newcastle",
                Id = 2,
                Orders = new List<Order>{
                    new Order{
                        Id = 400,
                        OrderItems = new List<string>{
                            "Salad",
                            "Taco",
                            "Pizza"
                        }
                    },
                    new Order{
                        Id = 401,
                        OrderItems = new List<string>{
                            "Cake",
                            "Taco",
                            "Pasta"
                        }
                    },
                    new Order{
                        Id = 402,
                        OrderItems = new List<string>{
                            "Salad",
                            "Pasta"
                        }
                    }
                }
            }
        };
        Console.WriteLine($"Neighbourhoods: {status.Count}");
        foreach(var neighbourhood in status){
            Console.WriteLine($"Neighbourhood: {neighbourhood.Name}");
            Console.WriteLine($"Total Orders: {neighbourhood.Orders.Count}");

            var allOrderItems = neighbourhood.Orders.SelectMany(i => i.OrderItems).ToList();
            Console.WriteLine($"Total Ordered Items: {allOrderItems.Count}");
            
            var groupedOrderItems = allOrderItems
                .GroupBy(i=>i)
                .Select(i => new {
                        Name = i.Key,
                        Total = i.Count()
                    })
                .OrderBy(i => i.Name)
                .ToList();
            
            foreach(var groupedOrderItem in groupedOrderItems){
                Console.WriteLine($"Order Item: {groupedOrderItem.Name} ({groupedOrderItem.Total})");
            }
        }
    }
}

public class Neighbourhood{
        public string Name {get;set;}
        public int Id {get;set;}
        public List<Order> Orders;

        public Neighbourhood(){
            Orders = new List<Order>();
        }
    }

public class Order{
    public int Id {get;set;}
    public List<string> OrderItems {get;set;}
    
    public Order(){
        OrderItems = new List<string>();
    }
}

见：https://dotnetfiddle.net/kN103N

输出：

Neighbourhoods: 2
Neighbourhood: Cherryhood
Total Orders: 3
Total Ordered Items: 9
Order Item: Burger (1)
Order Item: Cake (1)
Order Item: Pasta (2)
Order Item: Pizza (1)
Order Item: Salad (2)
Order Item: Taco (2)
Neighbourhood: Newcastle
Total Orders: 3
Total Ordered Items: 8
Order Item: Cake (1)
Order Item: Pasta (2)
Order Item: Pizza (1)
Order Item: Salad (2)
Order Item: Taco (2)

【讨论】：

我必须有 string[] HoodName = { "Cherryhood", "NewCastle", "Greenlight", "Summerlin", "Westcity", "Paradise", "Legions", "Flamingos" } ; int[] TeslimatSayisi = { 4, 2, 7, 2, 7, 3, 0, 1 };
TeslimatSayisi 表示每个社区的交付计数。
我认为您不应该将交付计数存储在这样的数组中。我假设您希望能够添加和删除交付。如果将计数存储在数组中，则始终必须返回并更新数组。像我上面那样构建数据会更有意义，这样您就可以随时查询计数并获取当前数字。
至于'我必须有string[]'：如果你真的需要，你仍然可以做到。我只是提供了一些示例代码来构建虚拟数据。更仔细地查看我提供的类，以及我为元素提取 Count 的 LINQ 查询/方式

【解决方案2】：

我注意到的第一件事是引擎盖类没有交货清单，所以我添加了一个。其次，我从主要方法中提取了方法，它们负责。结果就是这样：

    public static void Main()
    {
        initDictionary();
        printOutDeliveries();
    }

     static void printOutDeliveries()
    {
        foreach (var hood in hoods)
        {
            string foodNumbers="";
            foreach (var del in hood.Value.Deliveries)
            {
               foodNumbers += del.food + ": " + del.count + ", ";
            }
            Console.WriteLine("Hood: " + hood.Key + " | Deliver Count: " + hood.Value.Number + " Foods count: "+foodNumbers);

        }
    }

     static Dictionary<string, Hood> hoods = new Dictionary<string, Hood>();

     static void initDictionary()
    {
        string[] HoodName = { "Cherryhood", "NewCastle", "Greenlight", "Summerlin", "Westcity", "Paradise", "Legions", "Flamingos" };
        int[] TeslimatSayisi = { 4, 2, 7, 2, 7, 3, 0, 1 };
        int i = 0;
        foreach (var name in HoodName)
        {
            hoods.Add(name, new Hood()
            {
                Name = name,
                Number = TeslimatSayisi[i++],
                Deliveries = GetRandomDeliveries()
            });
        }
    }

    static List<delivery> GetRandomDeliveries()
    {
        List<string> foods = new List<string> { "Salat", "Taco", "Pizza", "Burger", "Pasta", "Cake" };
        List<delivery> deliveries = new List<delivery>();
        var randMaxVal = foods.Count - 1;
        var random = new Random();
        var forlooplength = random.Next(randMaxVal);
        for (int i = 0; i < forlooplength; i++)
        {
            var rand = random.Next(randMaxVal);
            deliveries.Add(new delivery()
            {
                food = foods[rand]
            });
            foods.RemoveAt(rand);
        }
        return deliveries;
    }

internal class delivery
{
    public string food;
    public int count => new Random().Next(10);
}
internal class Hood
{
    public string Name;
    public int Number;
    public List<delivery> Deliveries;
}

【讨论】：

哟兄弟感谢您的帮助。我尝试在我的编译器上运行代码，但出现了很多错误。我按照编译器的建议修复了错误，但是当我运行代码时，我没有得到任何输出。

【解决方案3】：

我对我的代码进行了一些更改，并部分解决了它。这是我的代码：

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace temp

{

    internal class delivery
    {
        public string food;
        public int count;

    }
    internal class Hood
    {
        public List<delivery> deliveryList;
        public string Name;
        public int Number;
    }
    class program
    {
        static void Main(string[] args)

        {
            List<string> food_names = new List<string> { "Burger", "Pizza", "Toast", "Chicken", "Taco", "Ice Cream", "Tomato", "Potato", "Salad" };
            List<int> max_food = new List<int> { 4, 5, 10, 7, 2, 6, 3, 7, 9 };
            ArrayList HoodName = new ArrayList(){
                    "Cherryhood", "NewCastle", "Greenlight", "Summerlin", "Westcity", "Paradise", "Legions", "Flamingos"
                };
            ArrayList TeslimatSayisi = new ArrayList() { 4, 2, 7, 2, 7, 3, 0, 1 };
            List<Hood> genericList = new List<Hood>();
            Hood ClassExample;

            for (int i = 0; i < HoodName.Count; i++)
            {
                ClassExample = new Hood();
                ClassExample.deliveryList = new List<delivery>();
                ClassExample.Name = (string)HoodName[i];
                ClassExample.Number = (int)TeslimatSayisi[i];
                genericList.Add(ClassExample);
            }

            foreach (Hood element in genericList)
            {
                delivery delivery_example;
                for (int i = 0; i < element.Number; i++)
                {
                    delivery_example = new delivery();
                    delivery_example.food = "Burger";
                    delivery_example.count = 5;
                    element.deliveryList.Add(delivery_example);
                }
            }

            foreach (Hood temp in genericList)
            {
                List<string> copy1 = food_names.ToList();
                List<int> copy2 = max_food.ToList();
                string temp1 = "Foods, count: ";
                Random rnd = new Random();
                foreach (delivery d in temp.deliveryList)
                {
                    if (copy1.Count != 0)
                    {
                        int r = rnd.Next(copy1.Count);
                        string food = copy1[r];
                        string num = copy2[r].ToString();
                        copy1.Remove(food);
                        copy2.Remove(int.Parse(num));
                        temp1 += food;
                        temp1 += ":";
                        temp1 += num;
                        temp1 += ", ";
                    }
                    else
                    {
                        temp1 += "Ran out of food, ";
                    }

                }
                Console.WriteLine("Hood: " + temp.Name + " | " + " Delivery Count: " + temp.Number + " | " + temp1);
            }
        }
    }
}

输出：

Hood: Cherryhood |  Delivery Count: 4 | Foods, count: Ice Cream:6, Potato:7, Chicken:2, Salad:9,
Hood: NewCastle |  Delivery Count: 2 | Foods, count: Ice Cream:6, Burger:4,
Hood: Greenlight |  Delivery Count: 7 | Foods, count: Burger:4, Taco:2, Salad:9, Tomato:3, Pizza:5, Chicken:7, Ice Cream:6,
Hood: Summerlin |  Delivery Count: 2 | Foods, count: Salad:9, Potato:7,
Hood: Westcity |  Delivery Count: 7 | Foods, count: Burger:4, Ice Cream:6, Taco:2, Tomato:3, Toast:10, Pizza:5, Chicken:7,
Hood: Paradise |  Delivery Count: 3 | Foods, count: Ice Cream:6, Salad:9, Toast:10,
Hood: Legions |  Delivery Count: 0 | Foods, count:
Hood: Flamingos |  Delivery Count: 1 | Foods, count: Potato:7,

【讨论】：