c# - 使用 linq 转换对象

Question

A 类具有以下属性：

public int A_Id { get; set; }
public IEnumerable<int> B_Ids { get; set; }

A 的集合包含：

A_Id = 1，B_Ids = {101、102、103}

A_Id = 2，B_Ids = {104}

A_Id = 3，B_Ids = {105, 106}

从上面的集合中，我想创建一个包含以下内容的新集合：

A_Id = 1，B_Id = 101

A_Id = 1，B_Id = 102

A_Id = 1，B_Id = 103

A_Id = 2，B_Id = 104

A_Id = 3，B_Id = 105

A_Id = 3，B_Id = 106

我怎么能通过使用 linq 做到这一点？

问候，迈克

Answer 1

使用SelectMany：

var result = list.SelectMany(a => a.B_Ids.Select(b => new { a.A_Id, B_Id = b }));

Answer 2

class ClassA
{
    public int A_Id { get; set; }
    public IEnumerable<int> B_Ids { get; set; }
}

var newAs = (from a in As from bId in a.B_Ids select new ClassA() {A_Id = a.A_Id, B_Ids = new int[] {bId}});