unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ScrollBox1: TScrollBox;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  i:integer;
  numPerCol,col: Integer;
  _left: Integer;
  _top: Integer;
  row: Integer;
  recnum, vspace: Integer;
  chk: TCheckBox;
begin
  col := 1;
  row := 1;
  recnum := 0;
  vspace := 15;  //行间距
  _left := 10;
  _top := 10;
  numPerCol:=10; //每列显示10个checkbox

  for i := 1 to 35 do
  begin
    inc(recnum);
    chk         := TCheckBox.Create(self.ScrollBox1);
    chk.Parent  := self.ScrollBox1;
    chk.Caption := IntToStr(i);
    chk.Tag     := i;
    if (recnum mod numPerCol = 0) then
    begin
      chk.Left := _left * col + chk.Width * (col - 1);

      if col > 1 then
        chk.Top := _top + chk.Height * (row - 1) +
          vspace * (row - 1)
      else
        chk.Top := _top * (col) + chk.Height *
          (row - 1) + vspace * (row - 1);

      inc(col);
      row := 1;
    end
    else
    begin
      chk.Left := _left * col + chk.Width * (col - 1);

      if col > 1 then
        chk.Top := _top + chk.Height *
          (row - 1) + vspace * (row - 1)
      else
        chk.Top := _top * (col) + chk.Height *
          (row - 1) + vspace * (row - 1);

      inc(row);
    end;
  end;
end;

end.