164 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			164 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
---
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id: 587d7fae367417b2b2512be6
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title: 渲染数据源的图像
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challengeType: 6
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forumTopicId: 18265
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dashedName: render-images-from-data-sources
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---
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# --description--
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前几个挑战中表明,JSON 数组中的每个对象都包含一个 `imageLink` 键,其值为猫图像的 URL。
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当你遍历这些对象的时候,你可以使用 `imageLink` 属性在 `img` 元素中显示此图像。
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这是执行此操作的代码:
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```js
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html += "<img src = '" + val.imageLink + "' " + "alt='" + val.altText + "'>";
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```
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# --instructions--
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添加代码以在 `img` 标记中使用 `imageLink` 和 `altText` 属性。
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# --hints--
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应该使用 `imageLink` 属性来显示图像。
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```js
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assert(code.match(/val\.imageLink/g));
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```
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应该使用 `altText` 作为图片的 `alt` 属性值。
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```js
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assert(code.match(/val\.altText/g));
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```
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# --seed--
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## --seed-contents--
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```html
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<script>
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  document.addEventListener('DOMContentLoaded', function(){
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    document.getElementById('getMessage').onclick = function(){
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      const req=new XMLHttpRequest();
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      req.open("GET",'/json/cats.json',true);
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      req.send();
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      req.onload = function(){
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        const json = JSON.parse(req.responseText);
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        let html = "";
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        json.forEach(function(val) {
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          html += "<div class = 'cat'>";
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          // Add your code below this line
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          // Add your code above this line
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          html += "</div><br>";
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        });
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        document.getElementsByClassName('message')[0].innerHTML=html;
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      };
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     };
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  });
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</script>
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<style>
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  body {
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    text-align: center;
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    font-family: "Helvetica", sans-serif;
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  }
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  h1 {
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    font-size: 2em;
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    font-weight: bold;
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  }
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  .box {
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    border-radius: 5px;
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    background-color: #eee;
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    padding: 20px 5px;
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  }
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  button {
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    color: white;
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    background-color: #4791d0;
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    border-radius: 5px;
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    border: 1px solid #4791d0;
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    padding: 5px 10px 8px 10px;
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  }
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  button:hover {
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    background-color: #0F5897;
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    border: 1px solid #0F5897;
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  }
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</style>
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<h1>Cat Photo Finder</h1>
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<p class="message box">
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  The message will go here
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</p>
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<p>
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  <button id="getMessage">
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    Get Message
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  </button>
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</p>
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```
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# --solutions--
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```html
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<script>
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  document.addEventListener('DOMContentLoaded', function(){
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    document.getElementById('getMessage').onclick = function(){
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      const req = new XMLHttpRequest();
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      req.open("GET",'/json/cats.json',true);
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      req.send();
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      req.onload = function(){
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        const json = JSON.parse(req.responseText);
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        let html = "";
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        json.forEach(function(val) {
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          html += "<div class = 'cat'>";
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          // Add your code below this line
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          html += "<img src = '" + val.imageLink + "' " + "alt='" + val.altText + "'>";
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          // Add your code above this line
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          html += "</div><br>";
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        });
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        document.getElementsByClassName('message')[0].innerHTML = html;
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      };
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     };
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  });
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</script>
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<style>
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  body {
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    text-align: center;
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    font-family: "Helvetica", sans-serif;
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  }
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  h1 {
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    font-size: 2em;
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    font-weight: bold;
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  }
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  .box {
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    border-radius: 5px;
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    background-color: #eee;
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    padding: 20px 5px;
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  }
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  button {
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    color: white;
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    background-color: #4791d0;
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    border-radius: 5px;
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    border: 1px solid #4791d0;
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    padding: 5px 10px 8px 10px;
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  }
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  button:hover {
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    background-color: #0F5897;
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    border: 1px solid #0F5897;
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  }
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</style>
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<h1>Cat Photo Finder</h1>
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<p class="message">
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  The message will go here
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</p>
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<p>
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  <button id="getMessage">
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    Get Message
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  </button>
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</p>
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```
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