VST Node mit Child Nodes hinzufügen (InitChildren)

[jus]

@Aviator: ok, vielen Dank für den Hinweis!

@DieDolly: ich habe daraus mal ein Beispielprojekt gebastelt, ist sicherlich noch verbesserungswürdig . Ich habe die Klassendefinition quasi von einem alten Beitrag von Stevie übernommen.

Delphi-Quellcode:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ContNrs, VirtualTrees;

type
  TNamedItem = class
  private
    fName: string;
    fItems: TObjectList;
  public
    constructor Create(const name: string);
    property Items: TObjectList read fItems;
    property Name: string read fName write fName;
  end;

  TNodeData = TNamedItem;
  PNodeData = ^TNodeData;

  TForm1 = class(TForm)
    VirtualStringTree1: TVirtualStringTree;
    procedure FormCreate(Sender: TObject);
    procedure VirtualStringTree1InitNode(Sender: TBaseVirtualTree; ParentNode,
      Node: PVirtualNode; var InitialStates: TVirtualNodeInitStates);
    procedure VirtualStringTree1InitChildren(Sender: TBaseVirtualTree;
      Node: PVirtualNode; var ChildCount: Cardinal);
    procedure VirtualStringTree1GetText(Sender: TBaseVirtualTree;
      Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;
      var CellText: WideString);
  private
    { Private-Deklarationen }
    FVstRootItemList: TObjectList;
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  folder1 : TNamedItem;
  folder1_1, folder1_2, folder1_3 : TNamedItem;
  folder1_1_1 : TNamedItem;
begin
  FVstRootItemList := TObjectList.Create;
  folder1 := TNamedItem.Create('Folder 1');
  folder1_1 := TNamedItem.Create('Folder 1.1');
  folder1_1_1 := TNamedItem.Create('Folder 1.1.1');
  folder1_1.Items.Add(folder1_1_1);
  folder1.Items.Add(folder1_1);
  FVstRootItemList.Add(folder1);

  folder1 := TNamedItem.Create('node');
  folder1_1 := TNamedItem.Create('subnode');
  folder1_2 := TNamedItem.Create('subnode');
  folder1_3 := TNamedItem.Create('subnode');
  folder1.Items.Add(folder1_1);
  folder1.Items.Add(folder1_2);
  folder1.Items.Add(folder1_3);
  FVstRootItemList.Add(folder1);

  folder1 := TNamedItem.Create('node');
  folder1_1 := TNamedItem.Create('subnode');
  folder1_2 := TNamedItem.Create('subnode');
  folder1_3 := TNamedItem.Create('subnode');
  folder1.Items.Add(folder1_1);
  folder1.Items.Add(folder1_2);
  folder1.Items.Add(folder1_3);
  FVstRootItemList.Add(folder1);

  VirtualStringTree1.NodeDataSize := SizeOf(TNodeData);
  VirtualStringTree1.RootNodeCount := FVstRootItemList.Count;
end;

procedure TForm1.VirtualStringTree1GetText(Sender: TBaseVirtualTree;
  Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;
  var CellText: WideString);
var
  data: PNodeData;
begin
  data:= Sender.GetNodeData(Node);
  if not assigned(data^) then exit;
  case Column of
    0: CellText := data^.Name;
  end;
end;

procedure TForm1.VirtualStringTree1InitChildren(Sender: TBaseVirtualTree;
  Node: PVirtualNode; var ChildCount: Cardinal);
var
  Data: PNodeData;
begin
  Data := Sender.GetNodeData(Node);
  ChildCount := Data^.items.Count;
end;

procedure TForm1.VirtualStringTree1InitNode(Sender: TBaseVirtualTree;
  ParentNode, Node: PVirtualNode; var InitialStates: TVirtualNodeInitStates);
var
  data: PNodeData;
  ParentData: PNodeData;
begin
  data := Sender.GetNodeData(Node);
  if VirtualStringTree1.GetNodeLevel(Node) = 0 then
    data^ := TNamedItem(FVstRootItemList[Node.Index])
  else
  begin
    ParentData := Sender.GetNodeData(ParentNode);
    data^ := TNamedItem(ParentData.items[Node.Index]);
  end;
  if data^.Items.Count > 0 then InitialStates := InitialStates + [ivsHasChildren];
end;

{ TNamedItem }
constructor TNamedItem.Create(const name: string);
begin
  fName := name;
  fItems := TObjectList.Create;
end;

end.

Im Anhang ist das ganze Projekt für Delphi 2007.

lg,
jus