在表佈局中檢測td中的焦點

Question

如果在某個表中沒有找到任何td的焦點，則該任務將採取行動。該表的佈局存儲在jQuery的變量，其佈局是這樣的

<table class="cal_tbl" cellSpacing="1" cellPadding="3"> <tbody> 
<tr> 
    <td class="cal_head">&lt;&lt;</td> 
    <td class="cal_head">&lt;</td> 
    <td class="cal_head" colSpan="3">November 2012</td> 
    <td class="cal_head">&gt;</td> 
    <td class="cal_head">&gt;&gt;</td> 
</tr> 
<tr> 
    <td class="cal_subhead">Sun</td> 
    <td class="cal_subhead">Mon</td> 
    <td class="cal_subhead">Tue</td> 
    <td class="cal_subhead">Wed</td> 
    <td class="cal_subhead">Thu</td> 
    <td class="cal_subhead">Fri</td> 
    <td class="cal_subhead">Sat</td> 
</tr> 
<tr> 
    <td colSpan="4"></td> 
    <td class="cal_cell">1</td> 
    <td class="cal_cell">2</td> 
    <td class="cal_cell">3</td> 
</tr> 
<tr> 
    <td class="cal_cell">4</td> 
    <td class="cal_cell">5</td> 
    <td class="cal_cell">6</td> 
    <td class="cal_cell">7</td> 
    <td class="cal_cell">8</td> 
    <td class="cal_cell">9</td> 
    <td class="cal_cell">10</td> 
</tr> 
<tr> 
    <td class="cal_cell">25</td> 
    <td class="cal_cell">26</td> 
    <td class="cal_cell">27</td> 
    <td class="cal_cell">28</td> 
    <td class="cal_cell">29</td> 
    <td class="cal_cell">30</td> 
</tr> </tbody></table> 

我要檢查的重點是在任何TD 下面的是我的代碼是我的嘗試

if ($(CurrentCalendarButton).children[i].is(":focus") == true) 
    alert("Keep it on") 

Answer 1

的問題是，在所有的DOM元素沒有實際接受焦點，並且它是由瀏覽器來決定哪些事情。見Which HTML elements can receive focus?

也許會對你TD懸停事件：

var hasFocus = false; 
$('td').hover(
    function() { hasFocus = true; alert('has focus !');}, 
    function() { hasFocus = false; alert('lost focus !');} 
);