使用Linq访问另一个对象中的对象属性

// 假设我们有两个类：Person和Address
public class Person
{
    public string Name { get; set; }
    public Address Address { get; set; }
}

public class Address
{
    public string City { get; set; }
    public string Street { get; set; }
}

// 创建一个Person对象集合
List<Person> persons = new List<Person>
{
    new Person { Name = "John", Address = new Address { City = "New York", Street = "123 Main St" } },
    new Person { Name = "Alice", Address = new Address { City = "London", Street = "456 Park Ave" } },
    new Person { Name = "Bob", Address = new Address { City = "Paris", Street = "789 Elm St" } }
};

// 使用Linq查询表达式访问另一个对象中的对象属性
var result1 = from person in persons
              select person.Address.City;

// 使用Linq方法链访问另一个对象中的对象属性
var result2 = persons.Select(person => person.Address.City);

// 输出结果
foreach (var city in result1)
{
    Console.WriteLine(city);
}

foreach (var city in result2)
{
    Console.WriteLine(city);
}