Tips dan Trik Delphi

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.Button8Click(Sender: TObject);
var i :integer;
begin
    for i:=0 to 9999999 do
    begin
        Label1.Caption := IntToStr(i);
        {.... loop main body here ...}
        Application.ProcessMessages;
        {ESC key stops the loop}
        if GetKeyState(VK_Escape) AND 128=128 then
           break;
    end;
end;

{Disable:}
EnableWindow(FindWindowEx(FindWindow('Progman', nil), HWND(0), 'ShellDll_DefView', nil),FALSE);

{Enable:}
EnableWindow(FindWindowEx(FindWindow('Progman', nil), HWND(0), 'ShellDll_DefView', nil),TRUE);

function ColorToHtml(DColor:TColor):string;
var
tmpRGB : TColorRef;
begin
      tmpRGB := ColorToRGB(DColor);
      Result:=Format('#%.2x%.2x%.2x', [GetRValue(tmpRGB), GetGValue(tmpRGB), GetBValue(tmpRGB)]);
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;

AddFontResource('c:\ FONTS\ MyFont.TTF');
SendMessage(HWND_BROADCAST, WM_FONTCHANGE, 0, 0);