C# UWP从IEnumerable中的嵌套列表获取值

我有一个包含嵌套“部分”列表的列表，如下所示：

private static IEnumerable<Section> Menu()
    {
        return new List<Section>()
        {
            new Section()
            {
                Name = "S1",
                Submenu = new List<Section>()
                {
                    new Section()
                    {
                        Name="S1A",
                    },
                    new Section()
                    {
                        Name="S1B",
                        Submenu = new List<Section>()
                        {
                            new Section()
                            {
                                Name = "S1BA",
                            },
                            new Section()
                            {
                                Name = "S1BB",
                            },
                            new Section()
                            {
                                Name = "S1BC",
                            }
                        }
                    },
                    new Section()
                    {
                        Name="S1C",
                    },
                    new Section()
                    {
                        Name="S1D",
                    },
                }
            },
            new Section()
            {
                Name = "S2",
                Submenu = new List<Section>()
                {
                    new Section()
                    {
                        Name = "S2A",
                    },
                    new Section()
                    {
                        Name = "S2B",
                    }
                }
            },
            new Section()
            {
                Name = "S3"
            },
        };
    }

问题是，当我将其更改为以下内容时：

string sectionName = "S1BC"
Section _section = Menu().First(u => u.Name == sectionName);

我收到一个错误，说什么也没找到

有没有办法做到这一点，或者我的做法是错误的

---

非常感谢

听起来你想递归地迭代你的分区树？您可以通过简单的深度优先搜索来实现这一点：

private static IEnumerable<Section> Flatten(IEnumerable<Section> sections)
{
    foreach (var section in sections)
    {
        // Yield the section itself
        yield return section;

        // Visit the section's subsections, and yield them all
        if (section.Submenu != null)
        {
            foreach (var subsection in Flatten(section.Submenu))
            {
                yield return subsection;
            }
        }
    }
}

private static IEnumerable<Section> Flatten(IEnumerable<Section> sections)
{
    foreach (var section in sections)
    {
        // Yield the section itself
        yield return section;

        // Visit the section's subsections, and yield them all
        if (section.Submenu != null)
        {
            foreach (var subsection in Flatten(section.Submenu))
            {
                yield return subsection;
            }
        }
    }
}

string sectionName = "S1BC"
Section _section = Flatten(Menu()).First(u => u.Name == sectionName);