161 lines
4.4 KiB
Markdown
161 lines
4.4 KiB
Markdown
|
---
|
|||
|
|
id: 587d7790367417b2b2512ab1
|
|||
|
|
title: 使用 tabindex 指定多個元素的鍵盤焦點順序
|
|||
|
|
challengeType: 0
|
|||
|
|
videoUrl: 'https://scrimba.com/c/cmzRRcb'
|
|||
|
|
forumTopicId: 301028
|
|||
|
|
dashedName: use-tabindex-to-specify-the-order-of-keyboard-focus-for-several-elements
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
# --description--
|
|||
|
|
|
|||
|
|
`tabindex` 屬性還可以指定元素的 tab 鍵焦點順序， 將它的值設置爲大於等於 1 的整數，就可以實現這個功能。
|
|||
|
|
|
|||
|
|
給元素設置 `tabindex="1"`，鍵盤將首先把焦點放在這個元素上。 然後它按照指定的 `tabindex` 值（2、3 等等）順序循環，再移動到默認值和 `tabindex="0"` 項目。
|
|||
|
|
|
|||
|
|
需要注意的是，使用這種方式設置 tab 鍵焦點順序會覆蓋默認順序，其中默認順序爲標籤在文檔流中出現的順序。 這可能會讓那些希望從頁面頂部開始導航的用戶感到困惑。 使用 tabindex 在某些情況下是必要的，但在使用時要充分考慮到頁面的可訪問性。
|
|||
|
|
|
|||
|
|
舉個例子：
|
|||
|
|
|
|||
|
|
```html
|
|||
|
|
<div tabindex="1">I get keyboard focus, and I get it first!</div>
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
```html
|
|||
|
|
<div tabindex="2">I get keyboard focus, and I get it second!</div>
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
# --instructions--
|
|||
|
|
|
|||
|
|
Camper Cat 在他的勵志名言頁面中有一個搜索區域，他打算使用 CSS 把這個區域定位在頁面的右上角。 Camper Cat 希望他的搜索（search）`input` 與提交（submit）`input` 表單控件是 tab 鍵焦點順序的前兩項。 請給 `search` `input` 添加 `tabindex` 屬性，將屬性值設置爲 `1`；給 `submit` `input` 添加一個 `tabindex` 屬性，將屬性值設置爲 `2`。
|
|||
|
|
|
|||
|
|
另一件需要注意的事情是，單擊元素時，某些瀏覽器可能會將你置於 tab 鍵焦點順序的中間位置。 頁面上已添加一個元素，以確保你始終從 tab 鍵焦點順序的開頭開始。
|
|||
|
|
|
|||
|
|
# --hints--
|
|||
|
|
|
|||
|
|
應給 `search` `input` 標籤添加一個 `tabindex` 屬性。
|
|||
|
|
|
|||
|
|
```js
|
|||
|
|
assert($('#search').attr('tabindex'));
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
應給 `submit` `input` 標籤添加一個 `tabindex` 屬性。
|
|||
|
|
|
|||
|
|
```js
|
|||
|
|
assert($('#submit').attr('tabindex'));
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
`search` `input` 標籤的 `tabindex` 屬性值應爲 1。
|
|||
|
|
|
|||
|
|
```js
|
|||
|
|
assert($('#search').attr('tabindex') == '1');
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
`submit` `input` 標籤的 `tabindex` 屬性值應爲 2。
|
|||
|
|
|
|||
|
|
```js
|
|||
|
|
assert($('#submit').attr('tabindex') == '2');
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
# --seed--
|
|||
|
|
|
|||
|
|
## --seed-contents--
|
|||
|
|
|
|||
|
|
```html
|
|||
|
|
<body>
|
|||
|
|
<div tabindex="1" class="overlay"></div>
|
|||
|
|
<header>
|
|||
|
|
<h1>Even Deeper Thoughts with Master Camper Cat</h1>
|
|||
|
|
<nav>
|
|||
|
|
<ul>
|
|||
|
|
<li><a href="">Home</a></li>
|
|||
|
|
<li><a href="">Blog</a></li>
|
|||
|
|
<li><a href="">Training</a></li>
|
|||
|
|
</ul>
|
|||
|
|
</nav>
|
|||
|
|
</header>
|
|||
|
|
<form>
|
|||
|
|
<label for="search">Search:</label>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<input type="search" name="search" id="search">
|
|||
|
|
<input type="submit" name="submit" value="Submit" id="submit">
|
|||
|
|
|
|||
|
|
|
|||
|
|
</form>
|
|||
|
|
<h2>Inspirational Quotes</h2>
|
|||
|
|
<blockquote>
|
|||
|
|
<p>“There's no Theory of Evolution, just a list of creatures I've allowed to live.”<br>
|
|||
|
|
- Chuck Norris</p>
|
|||
|
|
</blockquote>
|
|||
|
|
<blockquote>
|
|||
|
|
<p>“Wise men say forgiveness is divine, but never pay full price for late pizza.”<br>
|
|||
|
|
- TMNT</p>
|
|||
|
|
</blockquote>
|
|||
|
|
<footer>© 2018 Camper Cat</footer>
|
|||
|
|
</body>
|
|||
|
|
<style>
|
|||
|
|
body {
|
|||
|
|
height: 100%;
|
|||
|
|
margin: 0 !important;
|
|||
|
|
padding: 8px;
|
|||
|
|
}
|
|||
|
|
.overlay {
|
|||
|
|
margin: -8px;
|
|||
|
|
position: absolute;
|
|||
|
|
width: 100%;
|
|||
|
|
height: 100%;
|
|||
|
|
}
|
|||
|
|
</style>
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
# --solutions--
|
|||
|
|
|
|||
|
|
```html
|
|||
|
|
<body>
|
|||
|
|
<div tabindex="1" class="overlay"></div>
|
|||
|
|
<header>
|
|||
|
|
<h1>Even Deeper Thoughts with Master Camper Cat</h1>
|
|||
|
|
<nav>
|
|||
|
|
<ul>
|
|||
|
|
<li><a href="">Home</a></li>
|
|||
|
|
<li><a href="">Blog</a></li>
|
|||
|
|
<li><a href="">Training</a></li>
|
|||
|
|
</ul>
|
|||
|
|
</nav>
|
|||
|
|
</header>
|
|||
|
|
<form>
|
|||
|
|
<label for="search">Search:</label>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<input tabindex="1" type="search" name="search" id="search">
|
|||
|
|
<input tabindex="2" type="submit" name="submit" value="Submit" id="submit">
|
|||
|
|
|
|||
|
|
|
|||
|
|
</form>
|
|||
|
|
<h2>Inspirational Quotes</h2>
|
|||
|
|
<blockquote>
|
|||
|
|
<p>“There's no Theory of Evolution, just a list of creatures I've allowed to live.”<br>
|
|||
|
|
- Chuck Norris</p>
|
|||
|
|
</blockquote>
|
|||
|
|
<blockquote>
|
|||
|
|
<p>“Wise men say forgiveness is divine, but never pay full price for late pizza.”<br>
|
|||
|
|
- TMNT</p>
|
|||
|
|
</blockquote>
|
|||
|
|
<footer>© 2018 Camper Cat</footer>
|
|||
|
|
</body>
|
|||
|
|
<style>
|
|||
|
|
body {
|
|||
|
|
height: 100%;
|
|||
|
|
margin: 0 !important;
|
|||
|
|
padding: 8px;
|
|||
|
|
}
|
|||
|
|
.overlay {
|
|||
|
|
margin: -8px;
|
|||
|
|
position: absolute;
|
|||
|
|
width: 100%;
|
|||
|
|
height: 100%;
|
|||
|
|
}
|
|||
|
|
</style>
|
|||
|
|
```
|