focusin 和 focusout 事件冒泡，焦点和 blur 事件没有。这意味着您可以在表单字段的父元素上使用 focusin 和 focusout 。

The focusin and focusout events bubble, the focus and blur events doesn't. That means that you can use the focusin and focusout on the parent element of a form field.

演示： http://jsfiddle.net/pAp4E/

HTML：

<div class="parent">
    <input type="text" />
</div>

<div class="log"></div>

Javascript：

Javascript:

$('.parent')
    .focusin(function(){log('div focusin');})
    .focusout(function(){log('div focusout');})
    .focus(function(){log('div focus');})
    .blur(function(){log('div blur');});
$('input')
    .focusin(function(){log('input focusin');})
    .focusout(function(){log('input focusout');})
    .focus(function(){log('input focus');})
    .blur(function(){log('input blur');});

function log(str){
  $('.log').append($('<div/>').text(str));
}

当你运行它时，你会看到只有输入才能获得所有事件，父母只获得 focusin 和焦点事件。

When you run it, you see that only the input gets all the events, the parent only gets the focusin and focusout events.