Question

HTML

<div id="main"></div>

JS

var TestClass = function() {};
TestClass.prototype = {
    addElement: function(parentId) {
    var parent = document.querySelector('#' + parentId);
    var a = document.createElement('a');
    a.textContent = '+';
    a.href = '#';
    a.addEventListener('click', this.onElementClick, false); //nothing happens on click
    parent.innerHTML = a.outerHTML;
  },

  onElementClick: function() {
    console.log('dynamic element clicked');
  }
};

new TestClass().addElement('main'); // on DOM ready

输出

<div id="main"><a href="#">+</a></div>

Answer 1

您正在添加事件侦听器，但是您忘记添加元素。

我已将document.body.append(a)添加到addElement方法。

这导致以下代码：

var TestClass = function() {};
TestClass.prototype = {
    addElement: function(parentId) {
    var parent = document.querySelector('#' + parentId);
    var a = document.createElement('a');
    a.textContent = '+';
    a.href = '#';
    a.addEventListener('click', this.onElementClick, false);
    document.body.append(a);
    parent.innerHTML = a.outerHTML;
  },

  onElementClick: function() {
    console.log('dynamic element clicked');
  }
};

new TestClass().addElement('main'); // on DOM ready

Test it out here

Answer 2

像这样：

var TestClass = function() {};
TestClass.prototype = {
    addElement: function(parentId) {
    var parent = document.getElementById(parentId); //Changed to getElementById
    var a = document.createElement('a');
    a.textContent = '+';
    a.href = '#';
    a.addEventListener('click', this.onElementClick, false);
    parent.append(a); //Changed
  },

  onElementClick: function() {
    console.log('dynamic element clicked');
  }
};

new TestClass().addElement('main'); // on DOM ready

<div id="main"></div>

您没有将a添加到parent，而只是添加了HTML。

如何在原型中动态创建的元素中添加事件监听器？

2 个答案: