var
Form1: TForm1;
GlobalHint:THintWindow;
implementation
{$R *.dfm}
procedure TForm1.ComboBox1Change(Sender: TObject);
var
p: TPoint;
r: TRect;
ArrayHintString: array[0..255] of Char;
begin
if GlobalHint<>nil then GlobalHint.Free;
GlobalHint := THintWindow.Create(Form1 );
p:=ComboBox1.ClientOrigin;
r:=Bounds(0 , 25, ComboBox1.Width , 0 );
DrawText(GlobalHint.Canvas.Handle, StrPCopy(ArrayHintString, ComboBox1.Text ), -1, r, DT_CALCRECT or DT_LEFT or DT_WORDBREAK or DT_NOPREFIX);
OffsetRect(r,p.X, p.Y);
GlobalHint.ActivateHint(r ,ComboBox1.Text );
end;