C#的6种常用集合类

二.下面讲述6种常用集合

1.ArrayList类

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
            ArrayList al = new ArrayList();
            al.Add(100);//单个添加
foreach (int number in new int[6] { 9, 3, 7, 2, 4, 8 })
{
                al.Add(number);//集体添加方法一//清清月儿 http://blog.csdn.net/21aspnet/
            }
int[] number2 = new int[2] { 11,12 };
            al.AddRange(number2);//集体添加方法二
            al.Remove(3);//移除值为3的
            al.RemoveAt(3);//移除第3个
            ArrayList al2 = new ArrayList(al.GetRange(1, 3));//新ArrayList只取旧ArrayList一部份


            Console.WriteLine("遍历方法一:");
foreach (int i in al)//不要强制转换
{
                Console.WriteLine(i);//遍历方法一
            }

            Console.WriteLine("遍历方法二:");
for (int i = 0; i != al2.Count; i++)//数组是length
{
int number = (int)al2[i];//一定要强制转换
                Console.WriteLine(number);//遍历方法二

            }
        }
    }
}

2.Stack类

栈,后进先出。push方法入栈,pop方法出栈。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
            Stack sk = new Stack();
            Stack sk2 = new Stack();
foreach (int i in new int[4] { 1, 2, 3, 4 })
{
                sk.Push(i);//填充
                sk2.Push(i);
            }

foreach (int i in sk)
{
                Console.WriteLine(i);//遍历
            }

            sk.Pop();
            Console.WriteLine("Pop");
foreach (int i in sk)
{
                Console.WriteLine(i);
            }

            sk2.Peek();//弹出最后一项不删除//清清月儿 http://blog.csdn.net/21aspnet/
            Console.WriteLine("Peek");
foreach (int i in sk2)
{
                Console.WriteLine(i);
            }

while (sk2.Count != 0)
{
int i = (int)sk2.Pop();//清空
                sk2.Pop();//清空
            }
            Console.WriteLine("清空");
foreach (int i in sk2)
{
                Console.WriteLine(i);
            }
        }
    }
}

3.Queue类

队列,先进先出。enqueue方法入队列,dequeue方法出队列。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
            Queue qu = new Queue();
            Queue qu2 = new Queue();
foreach (int i in new int[4] { 1, 2, 3, 4 })
{
                qu.Enqueue(i);//填充
                qu2.Enqueue(i);
            }

foreach (int i in qu)
{
                Console.WriteLine(i);//遍历
            }

            qu.Dequeue();
            Console.WriteLine("Dequeue");
foreach (int i in qu)
{
                Console.WriteLine(i);
            }

            qu2.Peek();//弹出最后一项不删除
            Console.WriteLine("Peek");
foreach (int i in qu2)
{
                Console.WriteLine(i);
            }

while (qu2.Count != 0)
{
int i = (int)qu2.Dequeue();//清空
                qu2.Dequeue();//清空
            }
            Console.WriteLine("清空");
foreach (int i in qu2)
{
                Console.WriteLine(i);
            }
        }
    }
}

4.Hashtable类

哈希表,名-值对。类似于字典(比数组更强大)。哈希表是经过优化的,访问下标的对象先散列过。如果以任意类型键值访问其中元素会快于其他集合。GetHashCode()方法返回一个int型数据,使用这个键的值生成该int型数据。哈希表获取这个值最后返回一个索引,表示带有给定散列的数据项在字典中存储的位置。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace ConsoleApplication1
{
class Program
{
public static void Main()
{

// Creates and initializes a new Hashtable.
            Hashtable myHT = new Hashtable();
            myHT.Add("one", "The");
            myHT.Add("two", "quick");
            myHT.Add("three", "brown");
            myHT.Add("four", "fox");

// Displays the Hashtable.//清清月儿 http://blog.csdn.net/21aspnet/
            Console.WriteLine("The Hashtable contains the following:");
            PrintKeysAndValues(myHT);
        }


public static void PrintKeysAndValues(Hashtable myHT)
{
foreach (string s in myHT.Keys)
                Console.WriteLine(s);

            Console.WriteLine(" -KEY- -VALUE-");
foreach (DictionaryEntry de in myHT)
                Console.WriteLine(" {0}: {1}", de.Key, de.Value);
            Console.WriteLine();
        }
    }
}

5.SortedList类

与哈希表类似,区别在于SortedList中的Key数组排好序的。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace ConsoleApplication1
{
class Program
{
public static void Main()
{

            SortedList sl = new SortedList();
            sl["c"] = 41;
            sl["a"] = 42;
            sl["d"] = 11;
            sl["b"] = 13;

foreach (DictionaryEntry element in sl)
{
string s = (string)element.Key;
int i = (int)element.Value;
                Console.WriteLine("{0},{1}",s,i);
            }
        }
    }
}

6.NameValueCollection类

官方给NameValueCollection定义为特殊集合一类,在System.Collections.Specialized下。

System.Collections.Specialized下还有HybridDicionary类,建议少于10个元素用HybridDicionary,当元素增加会自动转为HashTable。

System.Collections.Specialized下还有HybridDicionary类,字符串集合。

System.Collections.Specialized下还有其他类大家可以各取所需!

言归正转主要说NameValueCollection,HashTable 和 NameValueCollection很类似但是他们还是有区别的,HashTable 的KEY是唯一性,而NameValueCollection则不唯一!

using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
namespace ConsoleApplication1
{

class Program
{

static void Main(string[] args)
{
            System.Collections.Hashtable ht = new System.Collections.Hashtable();
            ht.Add("DdpMDisplaySeq".Trim(), "Display Sequence".Trim());
            ht.Add("DdpMNameChi".Trim(), "Name (Chinese)".Trim());
            ht.Add("DdpMNameEng".Trim(), "Name (English)".Trim());
            ht.Add("Comment".Trim(), "Comment".Trim());
            ht.Add("DdpMMarketCode".Trim(), "Market Code".Trim());
foreach (object key in ht.Keys)
{
                Console.WriteLine("{0}/{1}    {2},{3}", key, ht[key], key.GetHashCode(), ht[key].GetHashCode());
            }
            Console.WriteLine(" ");//清清月儿 http://blog.csdn.net/21aspnet/
            NameValueCollection myCol = new NameValueCollection();
            myCol.Add("DdpMDisplaySeq".Trim(), "Display Sequence".Trim());
            myCol.Add("DdpMNameChi".Trim(), "Name (Chinese)".Trim());
            myCol.Add("DdpMNameChi".Trim(), "Name (English)".Trim());
            myCol.Add("Comment".Trim(), "Comment".Trim());
            myCol.Add("DdpMMarketCode".Trim(), "Market Code".Trim());
foreach (string key in myCol.Keys)
{
                Console.WriteLine("{0}/{1} {2},{3}", key, myCol[key], key.GetHashCode(), myCol[key].GetHashCode());
            }

        }

    }


}


原文地址:https://www.cnblogs.com/zhukezhuke/p/1539615.html