how to use tooltips function for buttons in toolbar?

//create toolbar
HWND CreateBar(HWND pare_wnd)
{
    INITCOMMONCONTROLSEX P;
    P.dwSize = sizeof(P);
    P.dwICC = ICC_BAR_CLASSES;
    if (InitCommonControlsEx(&P))
    {
        //MessageBoxA(NULL,"加载控件库成功！",NULL,MB_OK);
    }
    else
        MessageBoxA(NULL,"加载控件库失败！",NULL,MB_OK);
    HWND toolbar;
    RECT rt;
    GetClientRect(pare_wnd,&rt);
    toolbar  = CreateWindowEx(WS_EX_CLIENTEDGE,
                              TOOLBARCLASSNAME,
                              NULL,
                              WS_CHILD |WS_VISIBLE|TBSTYLE_TOOLTIPS|TBSTYLE_TRANSPARENT ,  //specify tooltips style
                              rt.left,
                              rt.top,
                              0,
                              0,
                              pare_wnd,
                              (HMENU)NULL,
                              hInst,
                              NULL);
    if (toolbar == NULL)
    {
        MessageBoxA(NULL,"","",MB_OK);
    }
    
    return toolbar;
}


//add button  to toolbar

            TBBUTTON arr[1];
             arr[0].iBitmap = I_IMAGENONE;
             arr[0].idCommand = IDM_ABOUT;
             arr[0].fsState = TBSTATE_ENABLED  ;
             arr[0].fsStyle = BTNS_CHECK  ;
             arr[0].dwData = 0;
             arr[0].iString = IS_INTRESOURCE(IDS_STRING129);

             SendMessage(toolbar,TB_BUTTONSTRUCTSIZE ,(WPARAM)(int)size,0);
             
             SendMessage(toolbar,TB_ADDBUTTONS,1,(LPARAM) (LPTBBUTTON)arr);