98 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			98 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
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| id: 587d7790367417b2b2512ab0
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| title: Use tabindex to Add Keyboard Focus to an Element
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| challengeType: 0
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| videoUrl: ''
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| localeTitle: 使用tabindex将键盘焦点添加到元素
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| ---
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| 
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| ## Description
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| <section id="description"> HTML <code>tabindex</code>属性有三个与元素键盘焦点相关的不同功能。当它在标签上时,它表示可以关注元素。值(一个正数,负数或零的整数)决定了行为。当用户在页面中进行选项卡时,某些元素(如链接和表单控件)会自动接收键盘焦点。它与HTML源标记中的元素的顺序相同。通过在其上放置<code>tabindex="0"</code>属性,可以将相同的功能赋予其他元素,例如<code>div</code> , <code>span</code>和<code>p</code> 。这是一个例子: <code><div tabindex="0">I need keyboard focus!</div></code> <strong>注意</strong> <br>负<code>tabindex</code>值(通常为-1)表示元素是可聚焦的,但键盘无法访问。此方法通常用于以编程方式将焦点集中到内容上(例如,当激活用于弹出窗口的<code>div</code>时),并且超出了这些挑战的范围。 </section>
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| 
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| ## Instructions
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| <section id="instructions"> Camper Cat创建了一项新调查,以收集有关其用户的信息。他知道输入字段会自动获得键盘焦点,但他希望确保键盘用户在指示项目时暂停指示。将<code>tabindex</code>属性添加到<code>p</code>标记并将其值设置为“0”。奖金 - 使用<code>tabindex</code>还可以使CSS伪类<code>:focus</code>在<code>p</code>标签上工作。 </section>
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| 
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| ## Tests
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| <section id='tests'>
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| 
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| ```yml
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| tests:
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|   - text: 您的代码应该将<code>tabindex</code>属性添加到包含表单指令的<code>p</code>标记。
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|     testString: 'assert($("p").attr("tabindex"), "Your code should add a <code>tabindex</code> attribute to the <code>p</code> tag that holds the form instructions.");'
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|   - text: 您的代码应将<code>p</code>标记上的<code>tabindex</code>属性设置为值0。
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|     testString: 'assert($("p").attr("tabindex") == "0", "Your code should set the <code>tabindex</code> attribute on the <code>p</code> tag to a value of 0.");'
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| 
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| ```
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| 
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| </section>
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| 
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| ## Challenge Seed
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| <section id='challengeSeed'>
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| 
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| <div id='html-seed'>
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| 
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| ```html
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| <head>
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|   <style>
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|   p:focus {
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|     background-color: yellow;
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|   }
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|   </style>
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| </head>
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| <body>
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|   <header>
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|     <h1>Ninja Survey</h1>
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|   </header>
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|   <section>
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|     <form>
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| 
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| 
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|       <p>Instructions: Fill in ALL your information then click <b>Submit</b></p>
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| 
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| 
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|       <label for="username">Username:</label>
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|       <input type="text" id="username" name="username"><br>
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|       <fieldset>
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|         <legend>What level ninja are you?</legend>
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|         <input id="newbie" type="radio" name="levels" value="newbie">
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|         <label for="newbie">Newbie Kitten</label><br>
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|         <input id="intermediate" type="radio" name="levels" value="intermediate">
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|         <label for="intermediate">Developing Student</label><br>
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|         <input id="master" type="radio" name="levels" value="master">
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|         <label for="master">9th Life Master</label>
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|       </fieldset>
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|       <br>
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|       <fieldset>
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|       <legend>Select your favorite weapons:</legend>
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|       <input id="stars" type="checkbox" name="weapons" value="stars">
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|       <label for="stars">Throwing Stars</label><br>
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|       <input id="nunchucks" type="checkbox" name="weapons" value="nunchucks">
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|       <label for="nunchucks">Nunchucks</label><br>
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|       <input id="sai" type="checkbox" name="weapons" value="sai">
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|       <label for="sai">Sai Set</label><br>
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|       <input id="sword" type="checkbox" name="weapons" value="sword">
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|       <label for="sword">Sword</label>
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|       </fieldset>
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|       <br>
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|       <input type="submit" name="submit" value="Submit">
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|     </form><br>
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|   </section>
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|   <footer>© 2018 Camper Cat</footer>
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| </body>
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| 
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| ```
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| 
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| </div>
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| 
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| 
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| 
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| </section>
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| 
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| ## Solution
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| <section id='solution'>
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| 
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| ```js
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| // solution required
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| ```
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| </section>
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