c# - 从平面数据创建嵌套列表的最简单方法

Question

假设我有以下平面格式的信息，例如对象列表:

List<Line> lines = new List<Line>
                                   {
                                       new Line{Id = 1, Level = 0},
                                       new Line{Id = 2, Level = 1},
                                       new Line{Id = 3, Level = 1},
                                       new Line{Id = 4, Level = 2},
                                       new Line{Id = 5, Level = 2},
                                       new Line{Id = 6, Level = 1},
                                       new Line{Id = 7, Level = 1},
                                       new Line{Id = 8, Level = 2},
                                       new Line{Id = 9, Level = 1}
                                   };

每个对象都有一个 ID 和一个级别。我想以嵌套列表结束。为此，我有一个类(class)，可以根据级别列出 child 。

public class NestedLine
    {
        public int Id;
        public List<NestedLine> Children = new List<NestedLine>();
    }

将平面列表转换为嵌套列表的最简单方法是什么？

编辑:关于如何构建列表的唯一信息是行的顺序和级别。这应该是结果:

1
--2
--3
  --4
  --5
--6
--7
  --8
--9

Answer 1

这是我的尝试。

调用代码

List<Line> lines = new List<Line>
                           {
                               new Line{Id = 1, Level = 0},
                               new Line{Id = 2, Level = 1},
                               new Line{Id = 3, Level = 1},
                               new Line{Id = 4, Level = 2},
                               new Line{Id = 5, Level = 2},
                               new Line{Id = 6, Level = 1},
                               new Line{Id = 7, Level = 1},
                               new Line{Id = 8, Level = 2},
                               new Line{Id = 9, Level = 1}
                           };

NestedLine nestedLine = Recusrsive(lines, 0);

递归方法

private NestedLine Recusrsive(List<Line> lines, int listPos)
{
    NestedLine retVal = new NestedLine();
    Line line = lines[listPos];

    retVal.Id = line.Id;

    for (int iItem = listPos + 1; iItem < lines.Count; iItem++)
        if (lines[iItem].Level == line.Level + 1)
            retVal.Children.Add(Recusrsive(lines, iItem));
        else if (lines[iItem].Level <= line.Level) return retVal;

    return retVal;
}