C# List.Find()、List.FindAll()

List.Find() ：获取List中第一个符合条件的元素，并返回该元素；
List.FindAll() ：获取List中所有符合条件的元素，并最终返回一个列表。

 1 using System.Collections;
 2 using System.Collections.Generic;
 3 using UnityEngine;
 4 
 5 public class Test : MonoBehaviour
 6 {
 7     /// <summary>
 8     /// 所有学生
 9     /// </summary>
10     public List<Student> students = new List<Student>();
11 
12     private void Start()
13     {
14         //查找项羽
15         Debug.Log(FindStudent("项羽").ToString());
16 
17         //查找所有女性
18         foreach (var student in FilterFemales())
19         {
20             Debug.Log(student.ToString());
21         }
22     }
23     /// <summary>
24     /// 查找名为name的学生
25     /// </summary>
26     /// <param name="name">要查找的学生姓名</param>
27     Student FindStudent(string name)
28     {
29         /*//写法1
30         Student student = students.Find(delegate (Student stu)
31         {
32             return stu.name == name;
33         });*/
34 
35         //写法2
36         Student student = students.Find((Student stu) => stu.name == name);
37 
38         return student;
39     }
40     /// <summary>
41     /// 筛选所有女性学生
42     /// </summary>
43     List<Student> FilterFemales()
44     {
45         /*//写法1
46         List<Student> tempStudents = students.FindAll(delegate (Student stu)
47         {
48             return stu.gender == Gender.Female;
49         });*/
50 
51         //写法2
52         List<Student> tempStudents = students.FindAll((Student stu) => stu.gender == Gender.Female);
53 
54         return tempStudents;
55     }
56 }
57 /// <summary>
58 /// 学生信息
59 /// </summary>
60 [System.Serializable]
61 public class Student
62 {
63     /// <summary>
64     /// 名字
65     /// </summary>
66     public string name;
67     /// <summary>
68     /// 年龄
69     /// </summary>
70     public int age;
71     /// <summary>
72     /// 学号
73     /// </summary>
74     public int id;
75     /// <summary>
76     /// 性别
77     /// </summary>
78     public Gender gender;
79 
80     public override string ToString()
81     {
82         return string.Format("{0}，{1}，{2}，{3}", name, age, id, gender == Gender.Female ? "女" : "男");
83     }
84 }
85 /// <summary>
86 /// 性别
87 /// </summary>
88 public enum Gender
89 {
90     /// <summary>
91     /// 女性
92     /// </summary>
93     Female,
94     /// <summary>
95     /// 男性
96     /// </summary>
97     Male,
98 }