如何使用Linq将列表集合添加到列表中？

Question

我有一份清单

List<List<Employee>> EmployeeListCollection;

并希望

List<Employee> EmployeeList=//all employee in EmployeeListCollection

什么是查询？

Answer 1

List<Employee> EmployeeList = EmployeeListCollection.SelectMany(c => c).ToList();