c# - 如何使用 LINQ 获取包含在多个列表中的元素列表？

Question

假设我有代码:

  class Program
  {
    static void Main( string[] args )
    {
      Company companyA = new Company();
      Company companyB = new Company();
      companyA.Employees = new List<string> { "A1", "A2" };
      companyB.Employees = new List<string> { "B1", "B2" };

      List<Company> companyList = new List<Company> {companyA, companyB};
      List<string> allEmployees = new List<string>();
      foreach( Company company in companyList )
      {
        allEmployees.AddRange( company.Employees );
      }

      // ...
    }

    class Company
    {
      public List<string> Employees { get; set; }
    }
  }

我想用 companyList 中所有公司的员工填充 allEmployees。

如果不使用上述代码，是否可以通过对 companyList 对象使用单个 LINQ 语句来获得相同的结果？可能是这样的:

List<string> allEmployees  = companyList.Select( ...? )

Answer 1

使用SelectMany

List<string> allEmployees = companyList.SelectMany(x => x.Employees).ToList();