146 lines
4.2 KiB
C#
146 lines
4.2 KiB
C#
using System.Collections.Generic;
|
||
namespace Lesson16_List排序
|
||
{
|
||
class Program
|
||
{
|
||
static void Main(string[] args)
|
||
{
|
||
#region 知识点一 List自带的排序方法
|
||
List<int> list = new List<int>();
|
||
list.Add(3);
|
||
list.Add(2);
|
||
list.Add(4);
|
||
list.Add(6);
|
||
list.Add(5);
|
||
list.Add(1);
|
||
for (int i = 0; i < list.Count; i++)
|
||
{
|
||
Console.WriteLine(list[i]);
|
||
}
|
||
Console.WriteLine("_________________________");
|
||
//list提供了sort方法，可以对list进行排序，默认是升序排序
|
||
list.Sort();
|
||
for (int i = 0; i < list.Count; i++)
|
||
{
|
||
Console.WriteLine(list[i]);
|
||
}
|
||
//Arraylist中也有sort方法
|
||
#endregion
|
||
|
||
#region 知识点二 自定义类的排序
|
||
Console.WriteLine("_________________________");
|
||
List<Item> itemList = new List<Item>();
|
||
itemList.Add(new Item(45));
|
||
itemList.Add(new Item(10));
|
||
itemList.Add(new Item(99));
|
||
itemList.Add(new Item(24));
|
||
itemList.Add(new Item(100));
|
||
itemList.Add(new Item(12));
|
||
itemList.Sort();//无法排序，自定义类没有默认的排序规则，不知道按哪个字段排序
|
||
for (int i = 0; i < itemList.Count; i++)
|
||
{
|
||
Console.WriteLine(itemList[i].money);
|
||
}
|
||
#endregion
|
||
|
||
#region 知识点三 通过委托函数进行排序
|
||
List<ShopItem> shopItems = new List<ShopItem>();
|
||
shopItems.Add(new ShopItem(5));
|
||
shopItems.Add(new ShopItem(2));
|
||
shopItems.Add(new ShopItem(3));
|
||
shopItems.Add(new ShopItem(6));
|
||
shopItems.Add(new ShopItem(4));
|
||
shopItems.Add(new ShopItem(1));
|
||
|
||
//通过委托函数进行排序
|
||
//shopItems.Sort(SortShopItem);
|
||
|
||
//通过匿名函数表达式进行排序
|
||
//shopItems.Sort(delegate(ShopItem a,ShopItem b) {
|
||
// if (a.price > b.price)
|
||
// {
|
||
// return 1;
|
||
// }
|
||
// else if (a.price == b.price)
|
||
// {
|
||
// return 0;
|
||
// }
|
||
// else
|
||
// {
|
||
// return -1;
|
||
// }
|
||
//});
|
||
|
||
//通过lambda表达式结合三木运算符进行排序
|
||
shopItems.Sort((a, b) => {
|
||
return a.price > b.price ? 1 : -1;
|
||
});
|
||
|
||
Console.WriteLine("_________________________");
|
||
for (int i = 0; i < shopItems.Count; i++)
|
||
{
|
||
Console.WriteLine(shopItems[i].price);
|
||
}
|
||
#endregion
|
||
}
|
||
static int SortShopItem(ShopItem a,ShopItem b)
|
||
{
|
||
if (a.price > b.price)
|
||
{
|
||
return 1;
|
||
}else if (a.price == b.price)
|
||
{
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
return -1;
|
||
}
|
||
}
|
||
}
|
||
class Item : IComparable<Item>
|
||
{
|
||
public int money;
|
||
public Item(int money)
|
||
{
|
||
this.money = money;
|
||
}
|
||
|
||
public int CompareTo(Item other)
|
||
{
|
||
//返回值的含义：
|
||
//小于0：
|
||
//相当于放在当前对象前面
|
||
//等于0：
|
||
//保持当前的位置不变
|
||
//大于0：
|
||
//相当于放在当前对象后面
|
||
|
||
|
||
if ( this.money > other.money)
|
||
{
|
||
return 1;
|
||
}else if (this.money == other.money)
|
||
{
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
return -1;
|
||
}
|
||
}
|
||
}
|
||
class ShopItem
|
||
{
|
||
public int price;
|
||
public ShopItem(int price)
|
||
{
|
||
this.price = price;
|
||
}
|
||
}
|
||
}
|
||
//总结：
|
||
//系统自带的变量(int, float, double......) 一般都可以直接 Sort
|
||
// 自定义类 Sort 有两种方式
|
||
// 1. 继承接口 IComparable
|
||
// 2. 在 Sort 中传入委托函数 |