Tips dan Trik Delphi - Form

private
    { Private declarations }
  public
    { Public declarations }
     Edits: array[0..5] of TEdit;
  end;


procedure TForm1.FormCreate(Sender: TObject);
var
i: integer;
begin
    for i := 0 to 5 do
    begin
        Edits[i] := TEdit.Create(Self);
        with Edits[i] do
        begin
            Parent := Self;
            SetBounds(10, 10 + i*50, 200, 40);
            Tag := i; //each control should remember its index
            OnChange := EditChange; //same event handler for all controls
        end;
    end;
end;

procedure TForm1.EditChange(Sender: TObject);
var
i: integer;
begin
     i := TEdit(Sender).Tag;
     ShowMessage(Format('Anda menekan Edit[%d]',[i]));
end;

procedure TForm1.Panel1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
     ReleaseCapture;
     panel1.Perform(WM_SYSCOMMAND, $f012, 0)
end;

procedure TForm1.SetTransparent(hWnd: longint; value: byte);
var
style: integer;
begin
    style := GetWindowLong(hWnd, GWL_EXSTYLE);
    if value < 255 then
    begin
        style := style Or WS_EX_LAYERED;
        SetWindowLong(hWnd, GWL_EXSTYLE, style);
        SetLayeredWindowAttributes(hWnd, 0, value, LWA_ALPHA);
    end else
    begin
        style := style xor WS_EX_LAYERED;
        SetWindowLong(hWnd, GWL_EXSTYLE, style);
    end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
     SetTransparent(Handle, 200);
end;

procedure TForm1.SetTopmost(form: TForm; topmost: boolean);
begin
    if topmost then
       SetWindowPos(form.Handle, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE)
    else
       SetWindowPos(form.Handle, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
     SetTopmost(form1, true);
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  hSysMenu: HMENU;
begin
    hSysMenu := GetSystemMenu(Handle, false);
    EnableMenuItem(hSysMenu, SC_CLOSE, MF_BYCOMMAND or MF_GRAYED);
end;

procedure TForm1.ShowTitlebar(AForm: TForm; bShow: boolean);
var
style: longint;
begin
    with AForm do
    begin
          if BorderStyle = bsNone then exit;
          style := GetWindowLong(Handle, GWL_STYLE);
          if bShow then
          begin
              if (style and WS_CAPTION) = WS_CAPTION then exit;
              case BorderStyle of
                  bsSingle, bsSizeable:
                  SetWindowLong(Handle, GWL_STYLE, style or WS_CAPTION or WS_BORDER);
                  bsDialog:
                  SetWindowLong(Handle, GWL_STYLE, style or WS_CAPTION or DS_MODALFRAME or
                  WS_DLGFRAME);
              end;
          end else
          begin
              if (style and WS_CAPTION) = 0 then exit;
              case BorderStyle of
                  bsSingle, bsSizeable:
                  SetWindowLong(Handle, GWL_STYLE, style and (not(WS_CAPTION)) or WS_BORDER);
                  bsDialog:
                  SetWindowLong(Handle, GWL_STYLE, style and (not(WS_CAPTION)) or
                  DS_MODALFRAME or WS_DLGFRAME);
              end;
          end;
          SetWindowPos(Handle, 0, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE or SWP_NOZORDER or
          SWP_FRAMECHANGED or SWP_NOSENDCHANGING);
    end;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
   rgn: HRGN;
begin
    Form1.Color := clGreen;
    Form1.BorderStyle := bsNone;
    GetWindowRgn(Handle, rgn);
    DeleteObject(rgn);
    rgn:= CreateRoundRectRgn(0, 0, Width, Height, 100, 100);
    SetWindowRgn(Handle, rgn, TRUE);
end;

procedure TForm1.FormCreate(Sender: TObject);
var wleft, wRight : word;
begin
     wleft := 10;
     wRight := 10;
     Memo1.Perform(EM_SETMARGINS, EC_LEFTMARGIN or EC_RIGHTMARGIN, MAKELONG(wLeft, wRight));
end;

procedure TForm1.Edit1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
var
  Direction : Integer;
begin
    Direction := -1;
    case Key of
        VK_DOWN,VK_RETURN : Direction := 0; {Next}
        VK_UP : Direction := 1; {Previous}
    end;
    if Direction <> -1 then
    begin
        Perform(WM_NEXTDLGCTL, Direction, 0);
        Key := 0;
    end;
end;

procedure TForm1.FormPaint(Sender: TObject);
var Row, Ht:Word;
begin
    Ht := (ClientHeight + 255) div 256 ;
    for Row := 0 to 255 do
    with Canvas do begin
    Brush.Color := RGB(0, 0, Row);
    FillRect(Rect(0, Row * Ht,
    ClientWidth, (Row + 1) * Ht)) ;
    end;
end;