如何在 C# 中查找两个 Collections<T> 的差异

Question

我有以下两个合集class

public class ABC
{
   public int studentId {get;set;}
   public int schoolId {get;set;}
   // Class has other properties too both above two are the keys

}

现在我有两套ABC

  ICollection<ABC> C1 = {Some Data}
  ICollection<ABC> C2 = {Some Data}

我想根据键找到 C1 中不在 C2 中的 ABC 对象，即 StudentId 和 SchoolId

Answer 1

使用Except

var diff = C1.Except(C2)

另请注意，为了跟踪相等性，您可以重写 Equals 方法，或者实施 IEqualityComparer 并将其传递给 Except 方法

class ABCEqualityComparer : IEqualityComparer<ABC>
{
    public bool Equals(ABC b1, ABC b2)
    {
         return (b1.studentId == b2.studentId) && (b1.schoolId == b2.schoolId)
    }

    public int GetHashCode(ABC b)
    {
        return 7*b.studentId.GetHashCode() + b.schoolId.GetHashCode();
    }
}

你可以使用

var diff = C1.Except(C2, new ABCEqualityComparer())

如何在 C# 中查找两个 Collections<T> 的差异

How to find Difference in two Collections<T> in C#

linq

collections