Javascript 图片源更改 addEventListener "click"事件

Question

尝试使用 JavaScript 将图像源从 images/small/更改为 images/medium/

我已经尝试了以下代码，但由于某种原因，点击事件没有被拾取，感谢您对此的任何帮助。

Javascript

var thumbs = document.getElementById("thumbnails");

thumbs.addEventListener("click", function (i) {


    if (i.target.nodeName.toLowerCase() == "img") {
        // get image filename of clicked thumbnail
        var clickedImageSource = i.target.src;

        // replace the folder name of the image 
        var newSrc = clickedImageSource.replace("small","medium");


    }

});

HTML

<div id="thumbnails">
        <img src="images/small/Home.jpg" title="Home" />
        <img src="images/small/Office.jpg" title="Office" />
        <img src="images/small/Park.jpg" title="Park" />
        <img src="images/small/Hills.jpg" title="Hills" />
        <img src="images/small/HaveEyes.jpg" title="HaveEyes" />
    </div>

Answer 1

在 DOM 元素可用之前，您不能附加事件监听器。

<script>
  // executed before dom is ready.
  var thumbs = document.getElementById("thumbnails");

  thumbs.addEventListener("click", function(i) {
    console.log('clicked');
  });
</script>
<div id="thumbnails">
  <img src="images/small/Home.jpg" title="Home" />
  <img src="images/small/Office.jpg" title="Office" />
  <img src="images/small/Park.jpg" title="Park" />
  <img src="images/small/Hills.jpg" title="Hills" />
  <img src="images/small/HaveEyes.jpg" title="HaveEyes" />
</div>
<script>
  // executed after dom is ready.
  var thumbs = document.getElementById("thumbnails");

  thumbs.addEventListener("click", function(i) {
    console.log('clicked');
  });
</script>