Ausgabeliste in Baumstruktur

Question

Ich brauche eine rekursive Funktion in C# zu schreiben, die Daten in der Konsole in der folgenden Baumstruktur gedruckt werden:

-Continent 
--Country 
---Province 
----City1 
----- Suburb4 
------ House3 
----City2 
----- Suburb1 
----- Suburb2 
------ House1 
------ House6 
----- Suburb3 
------ House4 
------ House5 

ich einen Dataset Listenbereich habe wie folgt:

ID Description ParentID 
1 Continent Null 
2 Country  1 
3 Province 2 
4 City1  3 
5 Suburb1  6 
6 City2  3 
7 Suburb2  6 
8 Suburb3  6 
9 Suburb4  4 
10 House1  7 
11 House3  9 
12 House4  8 
13 House5  8 
14 House6  7 

Wie mache ich den Code unten erstellen diese Ausgabe?

class Program 
    { 
     static void Main(string[] args) 
     { 
      Console.WriteLine("Press any key to start..."); 
      Console.ReadKey(true); 

     var area = new List<Areas>(); 
     area = PopulateList(area); 

     area.Sort((s1,s2) => s1.ParentID.CompareTo(s2.ParentID)); 

     PrintData(area); 

     Console.WriteLine("Press any key to exit..."); 
     Console.ReadKey(true); 

    } 


    private static void PrintData(List<Areas> area) 
    { 
     Console.WriteLine("-" + area[0].Description); 
     string[] array = new string[13]; 

     foreach (var item in area) 
     { 
      string[] children = GetChildren(area, item); 
      if (children != null) 
      { 
       int count = 0; 
       foreach (var child in children) 
       { 
        if (child != null) 
        { 
         for (int i = 0; i <= count +1; i++) 
         { 
          Console.Write("-"); 
         } 

         int count2 = 0; 
         foreach (string x in array) 
         { 
          if ((x != null) && (x.Contains(children[count]))) 
          { 

          } 
          else 
          { 
           if (children[count2] != null) 
           { 
            Console.WriteLine(children[count2]); 

            array[count2] = children[count2]; 
            count2++; 
           } 
          } 
         } 
         count++; 

        } 
       } 
      } 
     } 

    } 

    private static string[] GetChildren(List<Areas> areas, Areas item) 
    { 
     string[] children = new string[13]; 
     int count = 0; 
     foreach (var area in areas) 
     { 
      if ((item.ID == area.ParentID) && (area.ParentID != 0)) 
      { 
       children[count] = area.Description; 
       count++; 

       foreach (var area2 in areas) 
       { 
        if ((area.ID == area2.ParentID) && (area2.ParentID != 0)) 
        { 
         children[count] = area2.Description; 
         //count++; 
         foreach (var area3 in areas) 
         { 
          if ((area.ID == area3.ParentID) && (area3.ParentID != 0)) 
          { 
           children[count] = area3.Description; 
           //count++; 
          } 
         } 
        } 
       } 
      } 

     } 
     return children; 
    } 

und ich bin eine Ausgabe wie folgt erhalten:

Ich habe folgend versucht

-Continent 
--Country 
Province 
---Country 
Province 
--Province 
City2 
---Province 
... 

Answer 1

Die folgende tut, was Sie wollen. Ich habe die Daten in eine generische Liste geladen, aber das Prinzip ist das gleiche

private List<Entity> _entities = new List<Entity>(); 


    private void Form1_Load(object sender, EventArgs e) 
    { 

     _entities.Add(new Entity(1, "Continent", null)); 
     _entities.Add(new Entity(2, "Country", 1)); 
     _entities.Add(new Entity(3, "Province", 2)); 
     _entities.Add(new Entity(4, "City1", 3)); 
     _entities.Add(new Entity(5, "Suburb1", 6)); 
     _entities.Add(new Entity(6, "City2", 3)); 
     _entities.Add(new Entity(7, "Suburb2", 6)); 
     _entities.Add(new Entity(8, "Suburb3", 6)); 
     _entities.Add(new Entity(9, "Suburb4", 4)); 
     _entities.Add(new Entity(10, "House1", 7)); 
     _entities.Add(new Entity(11, "House3", 9)); 
     _entities.Add(new Entity(12, "House4", 8)); 
     _entities.Add(new Entity(13, "House5", 8)); 
     _entities.Add(new Entity(14, "House6", 7)); 

     var parent = _entities.Find((x) => x.ParentId == 0); 
     EnumerateChildren(parent, 1); 
    } 

    private void EnumerateChildren(Entity thisEntity, int level) 
    { 
     Debug.WriteLine(new string('-', level) + thisEntity.Name); 
     foreach (var child in _entities.FindAll((x) => x.ParentId == thisEntity.Id).OrderBy(x => x.Id)) 
     { 
      EnumerateChildren(child, level + 1); 
     } 
    } 

    private class Entity 
    { 
     public int Id { get; set; } 
     public string Name { get; set; } 
     public int ParentId { get; set; } 
     public Entity(int id, string name, int? parentId) 
     { 
      this.Id = id; 
      this.ParentId = parentId.HasValue ? Convert.ToInt32(parentId) : 0; 
      this.Name = name; 
     } 
    } 

Answer 2

Ich würde die Umgebungsinfos in einem Dictionary<int, List<Area>> laden, wo die int Schlüssel einen ParentID und den List<Area> Wert steht für alle Kinder Bereiche der gegebenen darstellt ParentID.

zB:

struct Area { 
    public int ID; 
    public string Description; 
    public int? ParentID; 
} 

void OutputAreasTree() { 
    IEnumerable<Area> areas = GetAreasFromDataSource(); 
    OutputAreasTreeFromNode(LoadAreasByParentID(areas), areasByParentID[0][0], 1); 
} 

Dictionary<int, List<Area>> LoadAreasByParentID(IEnumerable<Area> areas) { 
    Dictionary<int, List<Area>> areasByParentID = new Dictionary<int, List<Area>>(); 
    foreach (Area area in areas) { 
     int parentID = area.ParentID ?? 0; // use 0 as the ParentID of the root 
     List<Area> children; 
     if (!areasByParentID.TryGetValue(parentID, out children)) { 
      children = new List<Area>(); 
      areasByParentID.Add(parentID, children); 
     } 
     children.Add(area); 
    } 
    return areasByParentID; 
} 

void OutputAreasTreeFromNode(Dictionary<int, List<Area>> areasByParentID, Area area, int depth) { 
    for (int i = 0; i < depth; i++) 
     Console.Write('-'); 
    Console.WriteLine(area.Description); 
    List<Area> children; 
    if (areasByParentID.TryGetValue(area.ID, out children)) { 
     foreach (Area child in children) 
      OutputAreasTreeFromNode(areasByParentID, child, depth+1); 
    } 
} 

Hoffe, es hilft.