List
- 排序(IComparer
) - 排序(Int32，Int32，IComparer
) - 种类()
- 排序(比较
)
在这里，在Set – 1中讨论了前两种方法。因此，我们将讨论最后两种方法。
Sort()方法
此方法用于使用默认比较器对整个List
Syntax: public void Sort ();
Exception: This method will give InvalidOperationException if the default Comparer cannot find an implementation of the IComparable
范例1：
// C# program to demonstrate the
// use of List.Sort() method
using System;
using System.Collections.Generic;
class GFG {
// Main Method
public static void Main()
{
// List initialize
List list1 = new List {
// list elements
1, 5, 6, 2, 4, 3
};
Console.WriteLine("Original List");
foreach(int g in list1)
{
// Display Original List
Console.WriteLine(g);
}
Console.WriteLine("\nSorted List");
// use of List.Sort() method
list1.Sort();
foreach(int g in list1)
{
// Display sorted list
Console.WriteLine(g);
}
}
}
输出：
Original List
1
5
6
2
4
3
Sorted List
1
2
3
4
5
6
范例2：
// C# program to demonstrate the
// use of List.Sort() method
using System;
using System.Collections.Generic;
class GFG {
// Main Method
public static void Main()
{
List list1 = new List();
// list elements
list1.Add("A");
list1.Add("I");
list1.Add("G");
list1.Add("B");
list1.Add("E");
list1.Add("H");
list1.Add("F");
list1.Add("C");
list1.Add("D");
Console.WriteLine("Original List");
// Display Original List
Display(list1);
Console.WriteLine("\nSorted List");
// use of List.Sort() method
list1.Sort();
// Display sorted List
Display(list1);
}
// Display function
public static void Display(List list)
{
foreach(string g in list)
{
Console.Write(g + " ");
}
}
}
输出：
Original List
A I G B E H F C D
Sorted List
A B C D E F G H I
范例3：
// C# program to demonstrate the
// use of List.Sort() method
using System;
using System.Collections.Generic;
public class GFG {
// Main Method
public static void Main()
{
// array elements
String[] list = {"C++", "Java", "C",
"Python", "HTML", "CSS",
"Scala", "Ruby", "Perl"};
var list1 = new List();
// "AddRange" method to add the
// string array elements into the List
list1.AddRange(list);
Console.WriteLine("List in unsorted order: ");
Display(list1);
Console.WriteLine(Environment.NewLine);
// using List.Sort() method
list1.Sort();
Console.WriteLine("List in sorted order: ");
Display(list1);
}
// Display method
static void Display(List list)
{
foreach(string g in list)
{
Console.Write(g + "\t");
}
}
}
输出：
List in unsorted order:
C++ Java C Python HTML CSS Scala Ruby Perl
List in sorted order:
C C++ CSS HTML Java Perl Python Ruby Scala
Sort(IComparer )方法
此方法用于使用指定的比较器对整个List
Syntax: public void Sort (Comparison
Parameter:
comparison: It is the IComparer
例外情况：
- ArgumentNullException：如果比较器为null，并且默认比较器Default无法找到类型T的IComparable
通用接口或IComparable接口的实现。 - ArgumentException：如果比较器的实现在排序期间导致错误。例如，比较器与其自身进行比较时可能不会返回0。
下面的程序说明了上述方法的用法：
范例1：
// C# program to demonstrate the use of
// List.Sort(comparison ) method
using System;
using System.Collections.Generic;
class GFG {
private static int Geek(string x,
string y)
{
if (x == null) {
if (y == null) {
// If x and y is null
// then they are equal
return 0;
}
else {
// If x is null but y is not
// null then y is greater.
return -1;
}
}
else {
if (y == null) {
return 1;
}
else {
// If the strings are of equal length,
// sort them with string comparison.
return x.CompareTo(y);
}
}
}
// Main Method
public static void Main()
{
List list1 = new List();
// list elemetns
list1.Add("AB");
list1.Add("CD");
list1.Add("GH");
list1.Add("EF");
list1.Add("IJ");
list1.Add("KL");
Console.WriteLine("Original List :");
// displaying original list
Display(list1);
Console.WriteLine("\nSort with generic Comparison object :");
// Sort(Comparison) method
//"Geek" is Comparison object
list1.Sort(Geek);
// displaying sorted list
Display(list1);
}
// display function
private static void Display(List list)
{
foreach(string g in list)
{
Console.WriteLine(g);
}
}
}
输出：
Original List :
AB
CD
GH
EF
IJ
KL
Sort with generic Comparison object :
AB
CD
EF
GH
IJ
KL
范例2：
// C# program to demonstrate the use of
// List.Sort(comparison ) method
using System;
using System.Collections.Generic;
class GFG {
private static int Geek(int x, int y)
{
if (x == 0) {
if (y == 0) {
// If x and y is null
// then they are equal
return 0;
}
else {
// If x is null but y is not
// null then y is greater.
return -1;
}
}
else {
if (y == 0) {
return 1;
}
else {
// If the strings are of equal length,
// sort them with string comparison.
return x.CompareTo(y);
}
}
}
public static void Main()
{
List list1 = new List();
// list elemetns
list1.Add(2);
list1.Add(5);
list1.Add(6);
list1.Add(4);
list1.Add(1);
list1.Add(3);
Console.WriteLine("Original List :");
// displaying original list
Display(list1);
Console.WriteLine("\nSort with generic "+
"Comparison object :");
// Sort(Comparison) method
//"Geek" is Comparison object
list1.Sort(Geek);
// displaying sorted list
Display(list1);
}
// display function
private static void Display(List list)
{
foreach(int g in list)
{
Console.WriteLine(g);
}
}
}
输出：
Original List :
2
5
6
4
1
3
Sort with generic Comparison object :
1
2
3
4
5
6
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.generic.list-1.sort?view=netframework-4.7.2