uses
Commctrl;

procedure ShowBalloonTip(Control: TWinControl; Icon: integer; Title: pchar; Text: PWideChar;
BackCL, TextCL: TColor);
const
TOOLTIPS_CLASS = 'tooltips_class32';
TTS_ALWAYSTIP = $01;
TTS_NOPREFIX = $02;
TTS_BALLOON = $40;
TTF_SUBCLASS = $0010;
TTF_TRANSPARENT = $0100;
TTF_CENTERTIP = $0002;
TTM_ADDTOOL = $0400 + 50;
TTM_SETTITLE = (WM_USER + 32);
ICC_WIN95_CLASSES = $000000FF;
type
TOOLINFO = packed record
cbSize: Integer;
uFlags: Integer;
hwnd: THandle;
uId: Integer;
rect: TRect;
hinst: THandle;
lpszText: PWideChar;
lParam: Integer;
end;
var
hWndTip: THandle;
ti: TOOLINFO;
hWnd: THandle;
begin
hWnd := Control.Handle;
hWndTip := CreateWindow(TOOLTIPS_CLASS, nil,
WS_POPUP or TTS_NOPREFIX or TTS_BALLOON or TTS_ALWAYSTIP,
0, 0, 0, 0, hWnd, 0, HInstance, nil);
if hWndTip <> 0 then
begin
SetWindowPos(hWndTip, HWND_TOPMOST, 0, 0, 0, 0,
SWP_NOACTIVATE or SWP_NOMOVE or SWP_NOSIZE);
ti.cbSize := SizeOf(ti);
ti.uFlags := TTF_CENTERTIP or TTF_TRANSPARENT or TTF_SUBCLASS;
ti.hwnd := hWnd;
ti.lpszText := Text;
Windows.GetClientRect(hWnd, ti.rect);
SendMessage(hWndTip, TTM_SETTIPBKCOLOR, BackCL, 0);
SendMessage(hWndTip, TTM_SETTIPTEXTCOLOR, TextCL, 0);
SendMessage(hWndTip, TTM_ADDTOOL, 1, Integer(@ti));
SendMessage(hWndTip, TTM_SETTITLE, Icon mod 4, Integer(Title));
end;
end;

{效果演示}

procedure TForm1.Button1Click(Sender: TObject);
begin
ShowBalloonTip(Button1, 1, '标题', '我在这里！', clBlue, clNavy