NEWBIE：從IEnumerable選擇2個或更多信息選擇

Question

新手在這裏，我的代碼有問題。在此代碼返回一個字符串數組（學生姓名）之前，但我需要添加學生ID而不需要我重新編碼整個方法。有人可以幫助我如何做到這一點？基本上我需要包含基於學生姓名的學生證。

TIA。

public Student[] GetAllStudents(string subject) 
    { 
     Student[] students = cache.GetAllStudents(subject); 

     if (students == null) 
     { 
      Subjects group = RetrieveSubjects(subject); 

      if (group != null) 
      { 
       students = group.Students.Select(r => r.StudentName).ToArray(); 
       // I need to include also the Student ID based on the Student Name queried above. 

      } 
      else 
      { 
       students = new string[0]; 
      } 

      cache.AddAllStudents(subject, students); 
     } 

     return students; 
    } 

Answer 1

您可以在選擇子句中使用匿名類，即

students = group.Students 
        .Select(r => new { name= r.StudentName, id= r.StudentID }) 
        .ToArray(); 

或者只選擇Student對象，它應該擁有所有你需要

students = group.Students.ToArray(); 

// doing .Select(r=>r) is redundant and can be omited 

似乎是你需要創建你的studentinfo類中的學生類，你會想在初始化器中改變道具。

students = group.Students 
        .Select(r => new Student { 
         StudentName= r.StudentName, 
         StudentID= r.StudentID 
        }) 
        .ToArray();