2018-10-10 18:03:03 -04:00
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---
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id: 587d7790367417b2b2512ab1
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2020-12-16 00:37:30 -07:00
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title: 使用 tabindex 指定多个元素的键盘焦点顺序
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2018-10-10 18:03:03 -04:00
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challengeType: 0
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2020-02-11 17:06:41 +08:00
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videoUrl: 'https://scrimba.com/c/cmzRRcb'
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forumTopicId: 301028
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2021-01-13 03:31:00 +01:00
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dashedName: use-tabindex-to-specify-the-order-of-keyboard-focus-for-several-elements
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2018-10-10 18:03:03 -04:00
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---
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2020-12-16 00:37:30 -07:00
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# --description--
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2021-02-06 04:42:36 +00:00
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`tabindex` 属性还可以指定元素的 tab 键焦点顺序， 将它的值设置为大于等于 1 的整数，就可以实现这个功能。
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2020-12-16 00:37:30 -07:00
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2021-02-06 04:42:36 +00:00
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给元素设置 `tabindex="1"`，键盘将首先把焦点放在这个元素上。 然后它按照指定的 `tabindex` 值（2、3 等等）顺序循环，再移动到默认值和 `tabindex="0"` 项目。
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2020-12-16 00:37:30 -07:00
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2021-02-06 04:42:36 +00:00
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需要注意的是，使用这种方式设置 tab 键焦点顺序会覆盖默认顺序，其中默认顺序为标签在文档流中出现的顺序。 这可能会让那些希望从页面顶部开始导航的用户感到困惑。 使用 tabindex 在某些情况下是必要的，但在使用时要充分考虑到页面的可访问性。
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2020-12-16 00:37:30 -07:00
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2020-02-11 17:06:41 +08:00
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举个例子：
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2018-10-10 18:03:03 -04:00
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2021-03-20 09:47:30 -06:00
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```html
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<div tabindex="1">I get keyboard focus, and I get it first!</div>
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```
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2020-12-16 00:37:30 -07:00
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2021-03-20 09:47:30 -06:00
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```html
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<div tabindex="2">I get keyboard focus, and I get it second!</div>
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```
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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# --instructions--
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2021-03-20 09:47:30 -06:00
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Camper Cat 在他的励志名言页面中有一个搜索区域，他打算使用 CSS 把这个区域定位在页面的右上角。 Camper Cat 希望他的搜索（search）`input` 与提交（submit）`input` 表单控件是 tab 键焦点顺序的前两项。 请给 `search` `input` 添加 `tabindex` 属性，将属性值设置为 `1`；给 `submit` `input` 添加一个 `tabindex` 属性，将属性值设置为 `2`。
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2020-12-16 00:37:30 -07:00
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2021-04-30 00:43:46 +09:00
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另一件需要注意的事情是，单击元素时，某些浏览器可能会将你置于 tab 键焦点顺序的中间位置。 页面上已添加一个元素，以确保你始终从 tab 键焦点顺序的开头开始。
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2020-12-16 00:37:30 -07:00
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# --hints--
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2021-02-06 04:42:36 +00:00
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应给 `search` `input` 标签添加一个 `tabindex` 属性。
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2020-12-16 00:37:30 -07:00
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```js
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assert($('#search').attr('tabindex'));
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2018-10-10 18:03:03 -04:00
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```
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2021-04-30 00:43:46 +09:00
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应给 `submit` `input` 标签添加一个 `tabindex` 属性。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```js
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assert($('#submit').attr('tabindex'));
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```
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2018-10-10 18:03:03 -04:00
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2021-02-06 04:42:36 +00:00
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`search` `input` 标签的 `tabindex` 属性值应为 1。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```js
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assert($('#search').attr('tabindex') == '1');
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```
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2018-10-10 18:03:03 -04:00
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2021-02-06 04:42:36 +00:00
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`submit` `input` 标签的 `tabindex` 属性值应为 2。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```js
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assert($('#submit').attr('tabindex') == '2');
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2018-10-10 18:03:03 -04:00
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```
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2020-02-11 17:06:41 +08:00
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2021-01-13 03:31:00 +01:00
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# --seed--
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## --seed-contents--
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```html
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<body>
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2021-04-30 00:43:46 +09:00
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<div tabindex="1" class="overlay"></div>
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2021-01-13 03:31:00 +01:00
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<header>
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<h1>Even Deeper Thoughts with Master Camper Cat</h1>
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<nav>
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<ul>
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<li><a href="">Home</a></li>
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<li><a href="">Blog</a></li>
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<li><a href="">Training</a></li>
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</ul>
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</nav>
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</header>
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<form>
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<label for="search">Search:</label>
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<input type="search" name="search" id="search">
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<input type="submit" name="submit" value="Submit" id="submit">
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</form>
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<h2>Inspirational Quotes</h2>
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<blockquote>
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<p>“There's no Theory of Evolution, just a list of creatures I've allowed to live.”<br>
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- Chuck Norris</p>
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</blockquote>
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<blockquote>
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<p>“Wise men say forgiveness is divine, but never pay full price for late pizza.”<br>
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- TMNT</p>
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</blockquote>
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<footer>© 2018 Camper Cat</footer>
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</body>
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2021-04-30 00:43:46 +09:00
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<style>
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body {
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height: 100%;
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margin: 0 !important;
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padding: 8px;
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}
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.overlay {
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margin: -8px;
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position: absolute;
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width: 100%;
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height: 100%;
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}
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</style>
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2021-01-13 03:31:00 +01:00
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```
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2020-12-16 00:37:30 -07:00
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# --solutions--
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2021-01-13 03:31:00 +01:00
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```html
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<body>
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2021-04-30 00:43:46 +09:00
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<div tabindex="1" class="overlay"></div>
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2021-01-13 03:31:00 +01:00
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<header>
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<h1>Even Deeper Thoughts with Master Camper Cat</h1>
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<nav>
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<ul>
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<li><a href="">Home</a></li>
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<li><a href="">Blog</a></li>
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<li><a href="">Training</a></li>
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</ul>
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</nav>
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</header>
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<form>
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<label for="search">Search:</label>
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<input tabindex="1" type="search" name="search" id="search">
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<input tabindex="2" type="submit" name="submit" value="Submit" id="submit">
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</form>
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<h2>Inspirational Quotes</h2>
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<blockquote>
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<p>“There's no Theory of Evolution, just a list of creatures I've allowed to live.”<br>
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- Chuck Norris</p>
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</blockquote>
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<blockquote>
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<p>“Wise men say forgiveness is divine, but never pay full price for late pizza.”<br>
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- TMNT</p>
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</blockquote>
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<footer>© 2018 Camper Cat</footer>
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</body>
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2021-04-30 00:43:46 +09:00
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<style>
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body {
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height: 100%;
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margin: 0 !important;
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padding: 8px;
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}
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.overlay {
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margin: -8px;
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position: absolute;
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width: 100%;
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height: 100%;
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}
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</style>
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2021-01-13 03:31:00 +01:00
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```
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