Question

新手在这里，我的代码有问题。在此代码返回一个字符串数组（学生名称）之前，我需要添加学生ID，而不需要我重新编码整个方法。有人可以帮我怎么做吗？基本上我需要根据学生姓名包含学生证。

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select子句中使用匿名类，即

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

或者只选择学生对象，因为它应该具备您所需要的一切

students = group.Students.ToArray();

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

似乎您需要从studentinfo类创建Student类，您可能希望在初始化程序中更改prop。

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

NEWBIE：从IEnumerable Select中选择2个或更多信息

1 个答案: