C#学习笔记（十九）：字典

自定义泛型

泛型类，第一替代符T，第二替代符U

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace m1w4d5_dictionary
{
    class Program
    {
        static void Main(string[] args)
        {
            //把数字转换成中文字符
            string inputStr = Console.ReadLine();
            //123456789
            //一二三四五
            //字典<key,value>
            //声明变量
            Dictionary<char, string> dic = new Dictionary<char, string>();
            dic.Add('1', "一");
            dic['2'] = "二";
            dic['3'] = "三";
            //修改一个元素
            //dic.Add('1',"壹");位置已占，会报错
            dic['2'] = "贰";
            //访问元素
            //Console.WriteLine(dic['2']);
            //遍历
            foreach (var item in dic)
            {
                //Console.WriteLine(item);
                if (item.Key == '1')
                {
                    Console.WriteLine(item.Value);
                }
            }
            Console.WriteLine();
            Dictionary<char, char> dic1 = new Dictionary<char, char>();
            string num = "1234567890";
            string str = "一二三四五六七八九零";
            for (int i = 0; i < num.Length; i++)
            {
                dic1[num[i]] = str[i];
            }
            for (int i = 0; i < inputStr.Length; i++)
            {
                //如果用户输入的key不在我们的范围内，会报错
                //通过ContainsKey判定字典中是否包含了对应的key
                if (dic1.ContainsKey(inputStr[i]))
                {
                    Console.Write(dic1[inputStr[i]]);
                }             
            }
            Console.WriteLine();
            //计算字符串中每个字母出现的次数"Welcome to China! Welcome to HangKang!"
            //我能通过字母（char）找到他出现的次数（int）
            Dictionary<char, int> dic2 = new Dictionary<char, int>();
            string str1 = "Welcome to China! Welcome to HangKang!";
            for (int i = 0; i < str1.Length; i++)
            {
                //如果你在字典有了，字典中有了这个字母
                if (dic2.ContainsKey(str1[i]))
                {
                    //你的值就自增
                    dic2[str1[i]]++;
                }
                else
                {
                    //你的值就是
                    dic2[str1[i]] = 1;
                }
               
            }
            foreach (var item in dic2)
            {
                Console.WriteLine(item.Key +":"+item.Value);
            }
        }
    }
}

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace 泛型
{
    //定义
    //泛型是C#的一种特性，可以让我们将一种结构（类，接口）或者一种逻辑（函数）应用到所有类型
    //如果我们要把一个类型或者方法写成泛型的，我们只需要在名称后面加上<>，<>中可以填入若干个类型替代符
    class MyList<T>
    {
        T[] data;
        public T this[int index]
        {
            get
            {
                if (index < 0 || index >= count)
                {
                    throw new OutOfMemoryException();
                }
                return data[index];
            }
            set
            {
                if (index < 0 || index >= count)
                {
                    throw new OutOfMemoryException();
                }
                else
                {
                    data[index] = value;
                }
            }
        }
        public int Capacity
        {
            get { return data.Length; }
            set
            {
                if (value == count) return;
                if (value < count) value = count;
                //建立新数组
                T[] newData = new T[value];
                //拷贝数据
                for (int i = 0; i < data.Length; i++) newData[i] = data[i];
                //用新数组换老数组
                data = newData;
            }
        }
        int count = 0;
        public int Count => count;
        //添加
        public MyList(int capacity = 4)
        {
            data = new T[capacity];
        }
        //动态增长    
        public void Add(T item)
        {
            if (count >= Capacity) Capacity *= 2;
            data[count] = item;
            count++;
        }
        //删除
        public void Remove(T item)
        {
            int index = IndexOf(item);
            if (index != -1)
            {
                RemoveAt(index);
            }
        }
        public void RemoveLast(T item)
        {
            int index = LastIndexOf(item);
            if (index != -1)
            {
                RemoveAt(index);
            }
        }
        public void RemoveAt(int index)
        {
            if (index >= count)
            {
                throw new IndexOutOfRangeException();
            }
            for (int i = index + 1; i < count; i++)
            {
                data[i - 1] = data[i];
            }
            count--;
        }
        public void RemoveAll(T item)
        {
            while (true)
            {
                int index = IndexOf(item);
                if (index != -1)
                {
                    RemoveAt(index);
                }
                else
                {
                    break;
                }
            }
        }
        //查找
        public int IndexOf(T item)
        {
            int index = -1;
            for (int i = 0; i < count; i++)
            {
                if (item.Equals(data[i]))
                {
                    return i;
                }
            }
            return index;
        }
        public int LastIndexOf(T item)
        {
            int index = -1;
            for (int i = count - 1; i >= 0; i--)
            {
                if (item.Equals(data[i]))
                {
                    return i;
                }
            }
            return index;
        }
        public void Sort(Comparison<T> comparison)
        {
            for (int i = 0; i < count - 1; i++)
            {
                for (int j = 0; j < count - 1 - i; j++)
                {
                    if (comparison(data[j], data[j + 1]) > 0)
                    {
                        T temp = data[j];
                        data[j] = data[j + 1];
                        data[j + 1] = temp;
                    }
                }
            }
        }
        public void Sort(IComparer<T> iCompareer)
        {
            for (int i = 0; i < count - 1; i++)
            {
                for (int j = 0; j < count - 1 - i; j++)
                {
                    if (iCompareer.Compare(data[j], data[j + 1]) > 0)
                    {
                        T temp = data[j];
                        data[j] = data[j + 1];
                        data[j + 1] = temp;
                    }
                }
            }
        }
        public void Sort()
        {
            for (int i = 0; i < count - 1; i++)
            {
                for (int j = 0; j < count - 1 - i; j++)
                {
                    IComparable<T> Icompar = data[j] as IComparable<T>;
                    if (Icompar.CompareTo(data[j + 1]) > 0)
                    {
                        T temp = data[j];
                        data[j] = data[j + 1];
                        data[j + 1] = temp;
                    }
                }
            }
        }
    }
    class Monster : IComparable<Monster>
    {
        public Monster(string name, int attack, int defend, int health)
        {
            this.name = name;
            this.attack = attack;
            this.defend = defend;
            this.health = health;
        }
        public string name;
        public int attack;
        public int defend;
        public int health;
        public override string ToString()
        {
            return string.Format("{0}:[attack:{1},defend:{2},health{3}]", name, attack, defend, health);
        }
        public int CompareTo(Monster other)
        {
            //比较某一个参数，返回对应值
            //如果大就返回大于0的数 自已排在对比参数的后面
            //如果小就返回小于0的数 自已排在对比参数的前面
            //如果相等就返回0 不换
            //这样在外部调用Sort的时候会 形成一个以这个参数为标准的升序排序
            return attack - other.attack;
        }
        public static int AttackSort(Monster a, Monster b)
        {
            return a.attack - b.attack;
        }
        public static int DefendSort(Monster a, Monster b)
        {
            return a.defend - b.defend;
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            //List<int> list = new List<int>();
            //list.Add(5);
            //list.Add(6);
            //list.Add(7);
            //list.Capacity = 0;
            //Console.WriteLine(list.Capacity);
            MyList<Monster> myList = new MyList<Monster>();
            Random roll = new Random();
            //Console.WriteLine(myList.Capacity);
            for (int i = 0; i < 10; i++)
            {
                myList.Add(new Monster(i.ToString(), roll.Next(5, 10), roll.Next(10, 15), roll.Next(100, 150)));
            }
            //myList[5] = 1;
            //myList[7] = 1;
            myList.Sort();
            for (int i = 0; i < myList.Count; i++)
            {
                Console.WriteLine(myList[i]);
            }
        }
    }
}