我有员工的集合

Class Employee

{
  empName
  empID
  empLoc 
  empPL
  empShift
}

我的列表中包含

My list contains

 empName,empID,empLoc,empPL,empShift
    E1,1,L1,EPL1,S1 
    E2,2,L2,EPL2,S2
    E3,3,L3,EPL3,S3
    E4,4,L1,EPL1,S1
    E5,5,L5,EPL5,S5
        E6,6,L2,EPL2,S2

我需要有不同的价值观的员工    empLoc，empPL，empShift。

I need to take the employees having distinct values empLoc,empPL,empShift.

有没有什么办法来实现这一目标使用LINQ？

Is there is any way to achieve this using LINQ ?

推荐答案

您可以实现自定义的IEqualityComparer<Employee>:

You could implement a custom IEqualityComparer<Employee>:

public class Employee
{
    public string empName { get; set; }
    public string empID { get; set; }
    public string empLoc { get; set; }
    public string empPL { get; set; }
    public string empShift { get; set; }

    public class Comparer : IEqualityComparer<Employee>
    {
        public bool Equals(Employee x, Employee y)
        {
            return x.empLoc == y.empLoc
                && x.empPL == y.empPL
                && x.empShift == y.empShift;
        }

        public int GetHashCode(Employee obj)
        {
            unchecked  // overflow is fine
            {
                int hash = 17;
                hash = hash * 23 + (obj.empLoc ?? "").GetHashCode();
                hash = hash * 23 + (obj.empPL ?? "").GetHashCode();
                hash = hash * 23 + (obj.empShift ?? "").GetHashCode();
                return hash;
            }
        }
    }
}

现在你可以使用这个超负荷的Enumerable.Distinct:

Now you can use this overload of Enumerable.Distinct:

var distinct = employees.Distinct(new Employee.Comparer());

少可重复使用，强大和有效的方法，使用匿名类型：

The less reusable, robust and efficient approach, using an anonymous type:

var distinctKeys = employees.Select(e => new { e.empLoc, e.empPL, e.empShift })
                            .Distinct();
var joined = from e in employees
             join d in distinctKeys
             on new { e.empLoc, e.empPL, e.empShift } equals d
             select e;
// if you want to replace the original collection
employees = joined.ToList();