Materialize CSS Dropdown 更新 DOM innerText

Question

我有一个使用 Materialize CSS 制作的下拉菜单。当用户单击它时，我试图更改“按钮”上的文本，但由于某种原因它不会更新 DOM。

var changeText;
changeText = function(){
  if(this.innerText === 'test'){
    this.innerText = 'success';
  } else {
    this.innerText = 'test';
  }
  
  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });
  
  console.log(this.innerText);
};

$( document ).ready(function() {

  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" rel="stylesheet"/>

<!-- Dropdown Trigger -->
<a class='dropdown-trigger btn' href='#' data-target='dropdown1'>Drop Me!</a>

<!-- Dropdown Structure -->
<ul id='dropdown1' class='dropdown-content'>
  <li><a href="#" onclick="changeText()">test</a></li>
</ul>

我已经尝试重新初始化下拉触发器，希望能够更新 DOM，但它没有任何效果。尽管您可以在控制台日志中看到，innerText 已按预期更改。

Answer 1

this 在这里引用窗口对象。所以试试event.target

var changeText;
changeText = function(){
  if(event.target.innerText === 'test'){
    event.target.innerText = 'success';
  } else {
    event.target.innerText = 'test';
  }  
  console.log(this.innerText);
};

$( document ).ready(function() {

  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" rel="stylesheet"/>

<!-- Dropdown Trigger -->
<a class='dropdown-trigger btn' href='#' data-target='dropdown1'>Drop Me!</a>

<!-- Dropdown Structure -->
<ul id='dropdown1' class='dropdown-content'>
  <li><a href="#" onclick="changeText()">test</a></li>
</ul>

Answer 2

要引用元素，您必须像下面这样传递引用

var changeText;
changeText = function(ele){
  if(ele.innerText === 'test'){
    ele.innerText = 'success';
  } else {
    ele.innerText = 'test';
  }

  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });

};

$( document ).ready(function() {

  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });
});





<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" rel="stylesheet"/>

<!-- Dropdown Trigger -->
<a class='dropdown-trigger btn' href='#' data-target='dropdown1'>Drop Me!</a>

<!-- Dropdown Structure -->
<ul id='dropdown1' class='dropdown-content'>
  <li><a href="#" onclick="changeText(this)">test</a></li>
</ul>

Answer 3

this指的是window，更新$('.dropdown-trigger')[0]的innerText：

var changeText;
changeText = function(e) {
  if (e.innerText === 'test') {
    $('.dropdown-trigger')[0].innerText = 'success';
  } else {
    $('.dropdown-trigger')[0].innerText = 'test';
  }

  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });
};

$(document).ready(function() {

  $('.dropdown-trigger').dropdown({
    alignment: 'right',
    constrainWidth: false,
    coverTrigger: false
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" rel="stylesheet" />

<!-- Dropdown Trigger -->
<a class='dropdown-trigger btn' href='#' data-target='dropdown1'>Drop Me!</a>

<!-- Dropdown Structure -->
<ul id='dropdown1' class='dropdown-content'>
  <li><a href="#" onclick="changeText(this)">test</a></li>
  <li><a href="#" onclick="changeText(this)">test 2</a></li>
</ul>