C#中数组Array，ArrayList，泛型List详细对比

using System;

namespace WebApp
{
  class Program
  {
    static void Main(string[] args)
    {
      //System.Array
      //1、数组[] 特定类型、固定长度
      string[] str1 = new string[3];
      str1[0] = "a";
      str1[1] = "b";
      str1[2] = "c";
      Console.WriteLine(str1[2]);

      string[] str2 = new string[] { "a", "b", "c" };
      Console.WriteLine(str2[0]);

      string[] str3 = { "a", "b", "c" };
      Console.WriteLine(str3[0]);
      //2、二维数组
      //int[,] intArray=new int[2,3]{{1,11,111},{2,22,222}};
      int[,] intArray = new int[2, 3];
      intArray[0, 0] = 1;
      intArray[0, 1] = 11;
      intArray[0, 2] = 111;

      intArray[1, 0] = 2;
      intArray[1, 1] = 22;
      intArray[1, 2] = 222;
      Console.WriteLine("{0},{1},{2}", intArray[0, 0], intArray[0, 1], intArray[0, 2]);
      Console.WriteLine("{0},{1},{2}", intArray[1, 0], intArray[1, 1], intArray[1, 2]);

      //3、多维数组
      int[, ,] intArray1 = new int[,,]
      {
        {{1, 1}, {11, 11}, {111, 111}},
        {{2, 2}, {22, 22}, {222, 222}},
        {{3, 3}, {33, 33}, {333, 333}}
      };
      Console.WriteLine("{0},{1},{2},{3},{4},{5}", intArray1[0, 0, 0], intArray1[0, 0, 1], intArray1[0, 1, 0], intArray1[0, 1, 1],
        intArray1[0, 2, 0], intArray1[0, 2, 1]);
      Console.WriteLine("{0},{1},{2},{3},{4},{5}", intArray1[1, 0, 0], intArray1[1, 0, 1], intArray1[1, 1, 0], intArray1[1, 1, 1],
        intArray1[1, 2, 0], intArray1[1, 2, 1]);
      Console.WriteLine("{0},{1},{2},{3},{4},{5}", intArray1[2, 0, 0], intArray1[2, 0, 1], intArray1[2, 1, 0], intArray1[2, 1, 1],
        intArray1[2, 2, 0], intArray1[2, 2, 1]);

      //4、交错数组即数组的数组
      int[][] intArray2 = new int[4][];
      intArray2[0] = new int[] { 1 };
      intArray2[1] = new int[] { 2, 22 };
      intArray2[2] = new int[] { 3, 33, 333 };
      intArray2[3] = new int[] { 4, 44, 444,4444 };
      for (int i = 0; i < intArray2.Length; i++)
      {
        for (int j = 0; j < intArray2[i].Length; j++)
        {
          Console.WriteLine("{0}", intArray2[i][j]);
        }
      }


      Console.ReadKey();
    }
  }
}

using System;
using System.Collections;
public class SamplesArrayList {

  public static void Main() {

   ArrayList myAL = new ArrayList();
   myAL.Add("Hello");
   myAL.Add("World");
   myAL.Add("!");

   Console.WriteLine( "myAL" );
   Console.WriteLine( "  Count:  {0}", myAL.Count );
   Console.WriteLine( "  Capacity: {0}", myAL.Capacity );
   Console.Write( "  Values:" );
   PrintValues( myAL );
  }

  public static void PrintValues( IEnumerable myList ) {
   foreach ( Object obj in myList )
     Console.Write( "  {0}", obj );
   Console.WriteLine();
   Console.ReadKey();
  }

}

      ArrayList list = new ArrayList();

      //add 
      list.Add("joye.net");
      list.Add(27);

      //update 
      list[2] = 28;

      //delete 
      list.RemoveAt(0);

      //Insert 
      list.Insert(0, "joye.net1"); 

using System;
using System.Collections.Generic;

public class Example
{
  public static void Main()
  {
    List<string> dinosaurs = new List<string>();

    Console.WriteLine("\nCapacity: {0}", dinosaurs.Capacity);

    dinosaurs.Add("Tyrannosaurus");
    dinosaurs.Add("Amargasaurus");
    dinosaurs.Add("Mamenchisaurus");
    dinosaurs.Add("Deinonychus");
    dinosaurs.Add("Compsognathus");

    Console.WriteLine();
    foreach(string dinosaur in dinosaurs)
    {
      Console.WriteLine(dinosaur);
    }

    Console.WriteLine("\nCapacity: {0}", dinosaurs.Capacity);
    Console.WriteLine("Count: {0}", dinosaurs.Count);

    Console.WriteLine("\nContains(\"Deinonychus\"): {0}",
      dinosaurs.Contains("Deinonychus"));

    Console.WriteLine("\nInsert(2, \"Compsognathus\")");
    dinosaurs.Insert(2, "Compsognathus");

    Console.WriteLine();
    foreach(string dinosaur in dinosaurs)
    {
      Console.WriteLine(dinosaur);
    }

    Console.WriteLine("\ndinosaurs[3]: {0}", dinosaurs[3]);

    Console.WriteLine("\nRemove(\"Compsognathus\")");
    dinosaurs.Remove("Compsognathus");

    Console.WriteLine();
    foreach(string dinosaur in dinosaurs)
    {
      Console.WriteLine(dinosaur);
    }

    dinosaurs.TrimExcess();
    Console.WriteLine("\nTrimExcess()");
    Console.WriteLine("Capacity: {0}", dinosaurs.Capacity);
    Console.WriteLine("Count: {0}", dinosaurs.Count);

    dinosaurs.Clear();
    Console.WriteLine("\nClear()");
    Console.WriteLine("Capacity: {0}", dinosaurs.Capacity);
    Console.WriteLine("Count: {0}", dinosaurs.Count);
  }
}

  public class ResultDTO<T>
  {
    public T Data { get; set; }
    public string Code { get; set; }
    public string Message { get; set; }
  }

      var data = new CityEntity();
      return new ResultDTO<CityEntity> { Data = data, Code = "1", Message = "sucess"};

      var data2 = new List<CityEntity>();
      return new ResultDTO<List<CityEntity>> { Data = data2, Code = "1", Message = "sucess" };

      var data1 = 1;
      return new ResultDTO<int> { Data = data1, Code = "1", Message = "sucess" };