代码示例:(标识:eg_js_addeventlistener_add_1)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript addEventListener()</h1>

<p>此示例使用 addEventListener() 方法将 click 事件附加到按钮。</p>

<button id="myBtn">试一试</button>

<script>
document.getElementById("myBtn").addEventListener("click", function() {
  alert("Hello World!");
});
</script>

</body>
</html>
运行结果: