CSharp_褚梓凡_无43

.vs/Homework/v17/DocumentLayout.json

@@ -0,0 +1,37 @@
+{
+  "Version": 1,
+  "WorkspaceRootPath": "D:\\Program Files\\Unity\\Projects\\CSharpHomework2025\\",
+  "Documents": [
+    {
+      "AbsoluteMoniker": "D:0:0:{FCF2C4E1-EB48-4D53-A8D7-EF81464309F4}|Homework\\Homework.csproj|d:\\program files\\unity\\projects\\csharphomework2025\\homework\\program.cs||{A6C744A8-0E4A-4FC6-886A-064283054674}",
+      "RelativeMoniker": "D:0:0:{FCF2C4E1-EB48-4D53-A8D7-EF81464309F4}|Homework\\Homework.csproj|solutionrelative:homework\\program.cs||{A6C744A8-0E4A-4FC6-886A-064283054674}"
+    }
+  ],
+  "DocumentGroupContainers": [
+    {
+      "Orientation": 0,
+      "VerticalTabListWidth": 256,
+      "DocumentGroups": [
+        {
+          "DockedWidth": 200,
+          "SelectedChildIndex": 0,
+          "Children": [
+            {
+              "$type": "Document",
+              "DocumentIndex": 0,
+              "Title": "Program.cs",
+              "DocumentMoniker": "D:\\Program Files\\Unity\\Projects\\CSharpHomework2025\\Homework\\Program.cs",
+              "RelativeDocumentMoniker": "Homework\\Program.cs",
+              "ToolTip": "D:\\Program Files\\Unity\\Projects\\CSharpHomework2025\\Homework\\Program.cs",
+              "RelativeToolTip": "Homework\\Program.cs",
+              "ViewState": "AgIAAGsBAAAAAAAAAAAcwIUBAAABAAAAAAAAAA==",
+              "Icon": "ae27a6b0-e345-4288-96df-5eaf394ee369.000738|",
+              "WhenOpened": "2025-08-10T11:53:05.294Z",
+              "EditorCaption": ""
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

Homework/Program.cs

@@ -9,7 +9,7 @@ namespace StudentManagementSystem
     public enum Grade
     {
         // TODO: 定义成绩等级 F(0), D(60), C(70), B(80), A(90)
-
+        F, D, C, B, A
     }
 
     // 泛型仓储接口
@@ -20,32 +20,40 @@ public interface IRepository<T>
         // Remove(T item) 返回bool
         // GetAll() 返回List<T>
         // Find(Func<T, bool> predicate) 返回List<T>
-
+        void Add(T item);
+        bool Remove(T item);
+        List<T> GetAll();
+        List<T> Find(Func<T, bool> predicate);
     }
 
     // 学生类
     public class Student : IComparable<Student>
     {
         // TODO: 定义字段 StudentId, Name, Age
-
-
+        public string StudentId { get; }
+        public string Name { get; }
+
+        public int Age { get; }
         public Student(string studentId, string name, int age)
         {
             // TODO: 实现构造方法，包含参数验证（空值检查）
-
+            StudentId = studentId ?? throw new ArgumentNullException(nameof(studentId));
+            Name = name ?? throw new ArgumentNullException(nameof(name));
+            Age = age > 0 ? age : throw new ArgumentException("年龄必须大于0");
         }
 
         public override string ToString()
         {
             // TODO: 返回格式化的学生信息字符串
-
+            return $"学号: {StudentId}, 姓名: {Name}, 年龄: {Age}";
         }
 
         // TODO: 实现IComparable接口，按学号排序
         // 提示：使用string.Compare方法
         public int CompareTo(Student? other)
         {
-
+            if (other == null) return 1;
+            return string.Compare(StudentId, other.StudentId, StringComparison.Ordinal);
         }
 
         public override bool Equals(object? obj)
@@ -63,18 +71,23 @@ public override int GetHashCode()
     public class Score
     {
         // TODO: 定义字段 Subject, Points
-
-
+        public string Subject { get; }
+        public double Points { get; }
+
+
         public Score(string subject, double points)
         {
             // TODO: 实现构造方法，包含参数验证
-
+            Subject = subject ?? throw new ArgumentNullException(nameof(subject));
+            Points = points >= 0 && points <= 100
+                ? points
+                : throw new ArgumentException("成绩必须在0-100之间");
         }
 
         public override string ToString()
         {
             // TODO: 返回格式化的成绩信息
-
+            return $"科目: {Subject}, 成绩: {Points}";
         }
     }
 
@@ -83,39 +96,56 @@ public class StudentManager : IRepository<Student>
     {
         // TODO: 定义私有字段存储学生列表
         // 提示：使用List<Student>存储
-
+        private List<Student> students = new List<Student>();
+
 
         public void Add(Student item)
         {
             // TODO: 实现添加学生的逻辑
             // 1. 参数验证
             // 2. 添加到列表
-
+            if (item == null) throw new ArgumentNullException(nameof(item));
+            if (students.Contains(item))
+                throw new InvalidOperationException("该学生已存在");
+            students.Add(item);
         }
 
         public bool Remove(Student item)
         {
             // TODO: 实现Remove方法
-
+            if (item == null) return false;
+            return students.Remove(item);
         }
 
         public List<Student> GetAll()
         {
             // TODO: 返回学生列表的副本
-
+            return new List<Student>(students);
         }
 
         public List<Student> Find(Func<Student, bool> predicate)
         {
             // TODO: 使用foreach循环查找符合条件的学生
-
+            var result = new List<Student>();
+            foreach (var student in students)
+            {
+                if (predicate(student))
+                    result.Add(student);
+            }
+            return result;
         }
 
         // 查找年龄在指定范围内的学生
         public List<Student> GetStudentsByAge(int minAge, int maxAge)
         {
             // TODO: 使用foreach循环和if判断实现年龄范围查询
-
+            var result = new List<Student>();
+            foreach (var student in students)
+            {
+                if (student.Age >= minAge && student.Age <= maxAge)
+                    result.Add(student);
+            }
+            return result;
         }
     }
 
@@ -124,41 +154,82 @@ public class ScoreManager
     {
         // TODO: 定义私有字段存储成绩字典
         // 提示：使用Dictionary<string, List<Score>>存储
-
+        private Dictionary<string, List<Score>> scores = new Dictionary<string, List<Score>>();
 
         public void AddScore(string studentId, Score score)
         {
             // TODO: 实现添加成绩的逻辑
             // 1. 参数验证
             // 2. 初始化学生成绩列表（如不存在）
             // 3. 添加成绩
-
+            if (string.IsNullOrEmpty(studentId))
+                throw new ArgumentNullException(nameof(studentId));
+            if (score == null)
+                throw new ArgumentNullException(nameof(score));
+
+            if (!scores.ContainsKey(studentId))
+                scores[studentId] = new List<Score>();
+
+            scores[studentId].Add(score);
         }
 
         public List<Score> GetStudentScores(string studentId)
         {
             // TODO: 获取指定学生的所有成绩
-
+            return scores.TryGetValue(studentId, out var studentScores)
+                ? new List<Score>(studentScores)
+                : new List<Score>();
         }
 
         public double CalculateAverage(string studentId)
         {
             // TODO: 计算指定学生的平均分
             // 提示：使用foreach循环计算总分，然后除以科目数
-
+            if (!scores.ContainsKey(studentId))
+                return 0;
+
+            double total = 0;
+            int count = 0;
+            foreach (var score in scores[studentId])
+            {
+                total += score.Points;
+                count++;
+            }
+            return count > 0 ? total / count : 0;
         }
 
         // TODO: 使用模式匹配实现成绩等级转换
         public Grade GetGrade(double score)
         {
-
+            return score switch
+            {
+                >= 90 => Grade.A,
+                >= 80 => Grade.B,
+                >= 70 => Grade.C,
+                >= 60 => Grade.D,
+                _ => Grade.F
+            };
         }
 
         public List<(string StudentId, double Average)> GetTopStudents(int count)
         {
             // TODO: 使用简单循环获取平均分最高的学生
             // 提示：可以先计算所有学生的平均分，然后排序取前count个
-
+            var averages = new List<(string, double)>();
+
+            foreach (var stu in scores)
+            {
+                double total = 0;
+                foreach (var score in stu.Value)
+                {
+                    total += score.Points;
+                }
+                double avg = stu.Value.Count > 0 ? total / stu.Value.Count : 0;
+                averages.Add((stu.Key, avg));
+            }
+
+            averages.Sort((x, y) => y.Item2.CompareTo(x.Item2));
+            return averages.Take(count).ToList();
         }
 
         public Dictionary<string, List<Score>> GetAllScores()
@@ -177,7 +248,11 @@ public void SaveStudentsToFile(List<Student> students, string filePath)
             try
             {
                 // 在这里实现文件写入逻辑
-
+                using var writer = new StreamWriter(filePath);
+                foreach (var student in students)
+                {
+                    writer.WriteLine($"{student.StudentId},{student.Name},{student.Age}");
+                }
             }
             catch (Exception ex)
             {
@@ -188,19 +263,32 @@ public void SaveStudentsToFile(List<Student> students, string filePath)
         public List<Student> LoadStudentsFromFile(string filePath)
         {
             List<Student> students = new List<Student>();
-            
+
             // TODO: 实现从文件读取学生数据
             // 提示：使用StreamReader，解析CSV格式
             try
             {
                 // 在这里实现文件读取逻辑
-
+                if (!File.Exists(filePath)) return students;
+
+                using var reader = new StreamReader(filePath);
+                string line;
+                while ((line = reader.ReadLine()) != null)
+                {
+                    var parts = line.Split(',');
+                    if (parts.Length != 3) continue;
+
+                    if (int.TryParse(parts[2], out int age))
+                    {
+                        students.Add(new Student(parts[0], parts[1], age));
+                    }
+                }
             }
             catch (Exception ex)
             {
                 Console.WriteLine($"读取文件时发生错误: {ex.Message}");
             }
-            
+
             return students;
         }
     }
@@ -230,33 +318,64 @@ static void Main(string[] args)
                 Console.WriteLine("\n2. 添加成绩信息:");
                 scoreManager.AddScore("2021001", new Score("数学", 95.5));
                 scoreManager.AddScore("2021001", new Score("英语", 87.0));
-                
+
                 scoreManager.AddScore("2021002", new Score("数学", 78.5));
                 scoreManager.AddScore("2021002", new Score("英语", 85.5));
-                
+
                 scoreManager.AddScore("2021003", new Score("数学", 88.0));
                 scoreManager.AddScore("2021003", new Score("英语", 92.0));
                 Console.WriteLine("成绩信息添加完成");
 
                 // 3. 测试年龄范围查询
                 Console.WriteLine("\n3. 查找年龄在19-20岁的学生:");
                 // TODO: 调用GetStudentsByAge方法并显示结果
-
+                var studentsInAgeRange = studentManager.GetStudentsByAge(19, 20);
+                foreach (var student in studentsInAgeRange)
+                {
+                    Console.WriteLine(student);
+                }
 
                 // 4. 显示学生成绩统计
                 Console.WriteLine("\n4. 学生成绩统计:");
                 // TODO: 遍历所有学生，显示其成绩、平均分和等级
-
+                foreach (var student in studentManager.GetAll())
+                {
+                    var scores = scoreManager.GetStudentScores(student.StudentId);
+                    double average = scoreManager.CalculateAverage(student.StudentId);
+                    Grade grade = scoreManager.GetGrade(average);
+
+                    Console.WriteLine($"学生: {student.Name}");
+                    foreach (var score in scores)
+                    {
+                        Console.WriteLine($"  {score}");
+                    }
+                    Console.WriteLine($"平均分: {average}, 等级: {grade}");
+                }
 
                 // 5. 显示排名（简化版）
                 Console.WriteLine("\n5. 平均分最高的学生:");
                 // TODO: 调用GetTopStudents(1)方法显示第一名
-
+                var topStudents = scoreManager.GetTopStudents(1);
+                if (topStudents.Count > 0)
+                {
+                    var theOne = topStudents[0];
+                    var student = studentManager.Find(s => s.StudentId == theOne.StudentId).First();
+                    Console.WriteLine($"{student.Name} 平均分: {theOne.Average:F2}");
+                }
 
                 // 6. 文件操作
                 Console.WriteLine("\n6. 数据持久化演示:");
                 // TODO: 保存和读取学生文件
-
+                string filePath = "students.csv";
+                dataManager.SaveStudentsToFile(studentManager.GetAll(), filePath);
+                Console.WriteLine($"学生数据已保存到: {filePath}");
+
+                var loadedStudents = dataManager.LoadStudentsFromFile(filePath);
+                Console.WriteLine($"从文件加载的学生数据 ({loadedStudents.Count} 个):");
+                foreach (var student in loadedStudents)
+                {
+                    Console.WriteLine(student);
+                }
 
             }
             catch (Exception ex)