集合

01.IList<>和IDictionary<>

02.Array / List / Dictionary之相互转换

string[] testAarray =new string[]{"array01", "array02", "array03", "array04", "array05" };
            List<string> testList=new List<string>() { "list01", "list02", "list03", "list04", "list05" };
            Dictionary<int,string> testDic=new Dictionary<int, string>() {{1,"dictionary01"}, { 2, "dictionary02" }, { 3, "dictionary03" } };

         
            string[] copyArray = new string[6];
            //字符串复制  参数 01.源数组 02.sourceIndex 此实例中的字符位置
            testAarray.CopyTo(copyArray,1);
            foreach (var item in copyArray)
            {
                WriteLine(item);
            }

//数组转List
            List<string> arrayToList=new List<string>(testAarray);
            foreach (var item in arrayToList)
            {
                WriteLine(item);
            }

//数组转字典

            Dictionary<int, string> arrayToDoc =
                testAarray.ToDictionary(arrayItem => System.Array.IndexOf(testAarray, arrayItem),
                    arrayItem => arrayItem);
            foreach (var item in arrayToDoc)
            {
                WriteLine(item);
            }

List<string> testList = new List<string>() { "list01", "list02", "list03", "list04", "list05" };

            //list转数组
            List<string> copyList=new List<string>(testList);
            string[] listToArray = copyList.ToArray();
            //List复制到Array
            //调用与Aarray.CopyTo相同，实现的功能貌似和List.ToArray()一样
            string[] listCopyToArray=new string[5];
            copyList.CopyTo(listCopyToArray,0);

Dictionary<int,string> testDic=new Dictionary<int, string>() {{1,"dictionary01"}, { 2, "dictionary02" }, { 3, "dictionary03" } };
        //Dictionary复制
        Dictionary<int, string> copyDic = new Dictionary<int, string>(testDic);
        //Dictionary转Array
        int[] dictionaryKeyToArray = testDic.Keys.ToArray<int>();
        string[] dictionaryToArray = testDic.Values.ToArray<string>();
        //Dictionary转List
        List<int> dictionaryKeyToList = testDic.Keys.ToList<int>();
        List<string> dictionaryToList = testDic.Values.ToList<string>();

03.list

升序和降序

List<int> list=new List<int>();
            list.Add(2);
            list.Add(3);
            list.Add(6);
            list.Add(5);
            list.Add(1);
            list.Add(8);
            list.Sort(); //升序排序
            foreach (var item in list)
            {
                WriteLine(item);
            }
            WriteLine();
            list.Reverse();// 反转顺序
            foreach (var item in list)
            {
                WriteLine(item);
            }

移除元素

list.Remove(2);//移除某个元素
 list.RemoveAt(2);//移除指定索引位置的元素

搜索list

List<int> list=new List<int>();
            list.Add(2);
            list.Add(3);
            list.Add(6);
            list.Add(5);
            list.Add(1);
            list.Add(8);
            list.Add(6);
            //01.是否包含某个元素
            bool contains=list.Contains(2);
            WriteLine(contains); //true

            //02.返回某个元素的索引位置 如果有相同的返回第一个
            int index =list.IndexOf(6);
            WriteLine(index);//2

            //03.返回某个元素的索引位置 如果有相同的返回最后一个索引
            int lastIndex = list.LastIndexOf(6);
            WriteLine(lastIndex);//6

            //04.
            list.Sort();
            int binaryIndex= list.BinarySearch(8);

、

List<int> result=list.FindAll((int value) => (value % 2) == 0);

            foreach (var item in result)
            {
                WriteLine(item); // 2 6 8 6
            }


int items=list.Find((value) => value == 8);
 WriteLine(items);//8

4. Dictionary

初始化

//01.是否包含键或值
            WriteLine(dictionary.ContainsKey(3)); //true
            WriteLine(dictionary.ContainsValue("白"));//true

            WriteLine("移除后");
            //02.通过key移除元素                                      
            dictionary.Remove(1);
            foreach (var dic in dictionary)
            {
                WriteLine(dic);
            }

static void Main(string[] args)
        {
            //初始化
            Dictionary<int, string> dictionary = new Dictionary<int, string>
            {
                {1, "red"},
                {2, "blue"},
                {3, "green"},
            };
            dictionary.Add(4, "pink");
            dictionary[5] = "purple";
            dictionary[3] = "白"; //更改key为3的
          
            Print(dictionary);
       

        }
        //结构体，定义可设置或检索的键/值对。也就是说我们可以通过 它记录一个键/值对这样的值
        //比如我们想定义一个ID(int类型)和Name(string类型)这样的键/值对，那么可以这样使用。
        static void Print(IEnumerable<KeyValuePair<int, string>> items)
        {
            foreach (KeyValuePair<int, string> item in items)
            {
               WriteLine(item.Key+":"+item.Value);
            }
        }

5.this做为索引器

class Program
    {
        static void Main(string[] args)
        {
            Pair<string> pair=new Pair<string>("一休","大熊");
            WriteLine(pair[PairItem.First]);
            WriteLine(pair[PairItem.Second]);
            ReadKey();
        }
    }

    interface IPair<T>
    {
        T First { get;}
        T Second { get;}
        T this[PairItem index] { get; }
    }

    public enum PairItem
    {
        First,
        Second,
    }

    public struct Pair<T> : IPair<T>
    {
        public T First { get; }
        public T Second { get; }

        public Pair(T First, T Second)
        {
            this.First = First;
            this.Second = Second;
        }
        public T this[PairItem index]
        {
            get
            {
                switch (index)
                {
                    case PairItem.First:
                        return First;
                    case PairItem.Second:
                        return Second;
                    default:
                        return default(T);
                }
            }
        }
    }