93 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			93 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | |||
|  | id: 587d7faa367417b2b2512bd4 | |||
|  | title: Add a Hover Effect to a D3 Element | |||
|  | required: | |||
|  |   - src: 'https://cdnjs.cloudflare.com/ajax/libs/d3/4.3.0/d3.min.js' | |||
|  | challengeType: 6 | |||
|  | videoUrl: '' | |||
|  | localeTitle: 将悬停效果添加到D3元素 | |||
|  | --- | |||
|  | 
 | |||
|  | ## Description
 | |||
|  | <section id="description">当用户用鼠标悬停在其上时,可以添加突出显示条形的效果。到目前为止,矩形的样式使用内置的D3和SVG方法,但您也可以使用CSS。使用<code>attr()</code>方法在SVG元素上设置CSS类。然后,新类的<code>:hover</code>伪类保存任何悬停效果的样式规则。 </section> | |||
|  | 
 | |||
|  | ## Instructions
 | |||
|  | <section id="instructions">使用<code>attr()</code>方法向所有<code>rect</code>元素添加一个<code>bar</code>类。将鼠标悬停在其上时,会将条形的<code>fill</code>颜色更改为棕色。 </section> | |||
|  | 
 | |||
|  | ## Tests
 | |||
|  | <section id='tests'> | |||
|  | 
 | |||
|  | ```yml | |||
|  | tests: | |||
|  |   - text: 你的<code>rect</code>元素应该有一类<code>bar</code> 。 | |||
|  |     testString: 'assert($("rect").attr("class") == "bar", "Your <code>rect</code> elements should have a class of <code>bar</code>.");' | |||
|  | 
 | |||
|  | ``` | |||
|  | 
 | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Challenge Seed
 | |||
|  | <section id='challengeSeed'> | |||
|  | 
 | |||
|  | <div id='html-seed'> | |||
|  | 
 | |||
|  | ```html | |||
|  | <style> | |||
|  |   .bar:hover { | |||
|  |     fill: brown; | |||
|  |   } | |||
|  | </style> | |||
|  | <body> | |||
|  |   <script> | |||
|  |     const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9]; | |||
|  | 
 | |||
|  |     const w = 500; | |||
|  |     const h = 100; | |||
|  | 
 | |||
|  |     const svg = d3.select("body") | |||
|  |                   .append("svg") | |||
|  |                   .attr("width", w) | |||
|  |                   .attr("height", h); | |||
|  | 
 | |||
|  |     svg.selectAll("rect") | |||
|  |        .data(dataset) | |||
|  |        .enter() | |||
|  |        .append("rect") | |||
|  |        .attr("x", (d, i) => i * 30) | |||
|  |        .attr("y", (d, i) => h - 3 * d) | |||
|  |        .attr("width", 25) | |||
|  |        .attr("height", (d, i) => 3 * d) | |||
|  |        .attr("fill", "navy") | |||
|  |        // Add your code below this line | |||
|  | 
 | |||
|  | 
 | |||
|  | 
 | |||
|  |        // Add your code above this line | |||
|  | 
 | |||
|  |     svg.selectAll("text") | |||
|  |        .data(dataset) | |||
|  |        .enter() | |||
|  |        .append("text") | |||
|  |        .text((d) => d) | |||
|  |        .attr("x", (d, i) => i * 30) | |||
|  |        .attr("y", (d, i) => h - (3 * d) - 3); | |||
|  | 
 | |||
|  |   </script> | |||
|  | </body> | |||
|  | 
 | |||
|  | ``` | |||
|  | 
 | |||
|  | </div> | |||
|  | 
 | |||
|  | 
 | |||
|  | 
 | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Solution
 | |||
|  | <section id='solution'> | |||
|  | 
 | |||
|  | ```js | |||
|  | // solution required | |||
|  | ``` | |||
|  | </section> |