Delphi VCL

Development Platform:
Delphi

MainForm.pas：Code Content
							unit MainForm;
interface
uses
  Windows, Messages, SysUtils, Classes, Graphics,
  Controls, Forms, Dialogs, Menus, ComCtrls, ToolWin, DBActns, ActnList,
  ImgList;
type
  TFormMain = class(TForm)
    ToolBar1: TToolBar;
    StatusBar1: TStatusBar;
    ImageList1: TImageList;
    ActionList1: TActionList;
    DataSetCancel1: TDataSetCancel;
    DataSetDelete1: TDataSetDelete;
    DataSetEdit1: TDataSetEdit;
    DataSetFirst1: TDataSetFirst;
    DataSetInsert1: TDataSetInsert;
    DataSetLast1: TDataSetLast;
    DataSetNext1: TDataSetNext;
    DataSetPost1: TDataSetPost;
    DataSetPrior1: TDataSetPrior;
    DataSetRefresh1: TDataSetRefresh;
    ToolButton1: TToolButton;
    ToolButton2: TToolButton;
    ToolButton3: TToolButton;
    ToolButton4: TToolButton;
    ToolButton5: TToolButton;
    ToolButton6: TToolButton;
    ToolButton7: TToolButton;
    ToolButton8: TToolButton;
    ToolButton9: TToolButton;
    ToolButton10: TToolButton;
    PageControl1: TPageControl;
    TabCompanies: TTabSheet;
    TabClasses: TTabSheet;
    TabFreeQ: TTabSheet;
    procedure FormCreate(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure PageControl1Change(Sender: TObject);
  public
    procedure ShowForm (Form: TForm; Tab: TTabSheet); overload;
  end;
var
  FormMain: TFormMain;
implementation
uses
  MainData, CompaniesForm,
  FreeQueryForm, ClassesForm;
{$R *.DFM}
procedure TFormMain.FormCreate(Sender: TObject);
begin
  ShortDateFormat := 'dd/mm/yyyy';
  ShowForm (TFormCompanies.Create (self), TabCompanies);
end;
procedure TFormMain.ShowForm (Form: TForm; Tab: TTabSheet);
begin
  Form.BorderStyle := bsNone;
  Form.Align := alClient;
  Form.Parent := Tab;
  Form.Show;
end;
procedure TFormMain.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
var
  i: integer;
begin
  // ask permission to close each subform
  CanClose := True;
  for i := 0 to Screen.FormCount - 1 do
    if Screen.Forms[I] <> self then
      CanClose := CanClose and Screen.Forms[I].CloseQuery;
end;
procedure TFormMain.PageControl1Change(Sender: TObject);
begin
  if PageControl1.ActivePage.ControlCount = 0 then
    if PageControl1.ActivePage = TabFreeQ then
      ShowForm (TFormFreeQuery.Create (self), TabFreeQ)
    else if PageControl1.ActivePage = TabClasses then
      ShowForm (TFormClasses.Create (self), TabClasses);
end;
end.

						