Question

我有一个List<Appointment>，充满了Appointment和Doctor类型的Patient对象。现在，我想遍历我的清单，以找出哪个医生的约会最多。

//Appointment objects
Appointment app1=new Appointment(doctor1, patient1);
Appointment app2=new Appointment(doctor2, patient3);
Appointment app2=new Appointment(doctor1, patient2);
Appointment app1=new Appointment(doctor3, patient4);

//All of the appointments are stored in this list 
List<Appointment>AllAppointments=new List<Appointment>();

//method for traversing the list
public void MostAppointments()
{
  //This returns an error: At least one obj must implement IComparable
  string find=AllAppointments.Max(x=>x.Doctor).ToString();
}

Answer 1

医生可能是一个复杂的对象，而不是数字值，因此Max无法对其进行操作。您还用错了。 Max返回Enumerable中的最大单个值，但是您希望出现最多的值。

我假设您的Doctor对象具有ID属性或类似内容。然后，您可以这样做：

add(E element)

如果医生只是一个字符串，则可以从GroupBy中删除.Id

Answer 2

我尝试了下面的代码，并且工作正常，您可以使用此代码：

//Appointment Class
    class Appointment
        {
            public string Doctor { get; set; }
            public string Patient { get; set; }
        }

static void Main(string[] args)
    {
        List<Appointment> appointments = new List<Appointment>();
        appointments.Add(new Appointment
        {
            Doctor = "doctor1",
            Patient = "patient1"
        });
        appointments.Add(new Appointment
        {
            Doctor = "doctor2",
            Patient = "patient1"
        });
        appointments.Add(new Appointment
        {
            Doctor = "doctor2",
            Patient = "patient2"
        });
        appointments.Add(new Appointment
        {
            Doctor = "doctor2",
            Patient = "patient3"
        });
        appointments.Add(new Appointment
        {
            Doctor = "doctor3",
            Patient = "patient1"
        });

        var result = appointments.GroupBy(x => x.Doctor).OrderByDescending(x=>x.Count()).Select(x=>x.Key).FirstOrDefault(); //doctor2


    }

希望对您有帮助。

谢谢

对象属性在列表中重复多少次

2 个答案: