unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons,
  VirtualTrees, Vcl.ImgList;

type
  TForm2 = class(TForm)
    ImageList1: TImageList;
    VST: TVirtualStringTree;
    BitBtn1: TBitBtn;
    procedure BitBtn1Click(Sender: TObject);
    procedure VSTGetImageIndexEx(Sender: TBaseVirtualTree; Node: PVirtualNode; Kind: TVTImageKind; Column: TColumnIndex; var Ghosted: Boolean; var ImageIndex: TImageIndex; var ImageList: TCustomImageList);
    procedure VSTGetNodeDataSize(Sender: TBaseVirtualTree;
    var NodeDataSize: Integer);
    procedure VSTGetText(Sender: TBaseVirtualTree; Node: PVirtualNode;
      Column: TColumnIndex; TextType: TVSTTextType; var CellText: string);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

type
  MyThread = class(TThread)
  private
    i:integer;
    { Private-Deklarationen }
  protected
    { protected-Deklarationen }
    procedure Execute; override;
    procedure DoSomething;
  public
    { Public-Deklarationen }
  end;

type
  PTreeData = ^TTreeData;
  TTreeData = packed record
  Column0: String; Column1: String; Column2: String;
end;

var
  MyThr: MyThread;
  Form2: TForm2;

implementation

{$R *.dfm}

procedure MyThread.Execute;
var
  Data: PTreeData;
  XNode: PVirtualNode;
  begin
 while not Terminated do
   begin
     inc(i);

   XNode := form2.VST.AddChild(nil);

   if form2.VST.AbsoluteIndex(XNode) > -1 then
     begin
       Data := form2.VST.GetNodeData(Xnode);
       Data^.Column0 := inttostr(i);
       Data^.Column1 := 'Wert 1';
       Data^.Column2 := 'Wert 2';
     end;

     if i = 10 then begin
        i:=0;
        SuspendThread(MyThr.Handle);
     end;

   Synchronize(DoSomething);
   end;
end;

procedure MyThread.DoSomething;
begin
//
end;

procedure TForm2.BitBtn1Click(Sender: TObject);
begin
       MyThr := MyThread.Create(True);
       MyThr.FreeOnTerminate := true;
       MyThr.Priority := tpIdle;
       ResumeThread(MyThr.Handle);
end;

procedure TForm2.VSTGetImageIndexEx(Sender: TBaseVirtualTree; Node: PVirtualNode; Kind: TVTImageKind; Column: TColumnIndex; var Ghosted: Boolean; var ImageIndex: TImageIndex; var ImageList: TCustomImageList);
begin
  if Column = 0 then
    begin
      if Kind in [ikNormal, ikSelected] then ImageIndex := 0;
  end;

end;

procedure TForm2.VSTGetNodeDataSize(Sender: TBaseVirtualTree; var NodeDataSize: Integer);
begin
  NodeDataSize := SizeOf(TTreeData);
end;

procedure TForm2.VSTGetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType; var CellText: string);
var
  Data: PTreeData;
begin
  Data := VST.GetNodeData(Node);
  case Column of
    0: CellText := Data^.Column0;
    1: CellText := Data^.Column1;
    2: CellText := Data^.Column2;
  end;
end;

end.

procedure TForm2.BitBtn1Click(Sender: TObject);
var
  Data: PTreeData;
  XNode: PVirtualNode;
begin
   XNode := VST.AddChild(nil);
   Data := VST.GetNodeData(Xnode);

   Data^.Column0 := inttostr(i);
   Data^.Column1 := 'Wert 1';
   Data^.Column2 := 'Wert 2';

end;