Question

我正在制作一个简单的清单应用。我想查找添加后已检查的任务，并对特定任务进行直通。我怎么做？

将更改事件绑定到创建的每个任务似乎效率低下。我如何从这里继续？

document.getElementById('taskForm').addEventListener('submit',displayTask);

function displayTask(e){
  let task = document.getElementById('taskInput').value;
  let div = document.createElement('div');

  div.innerHTML = `<input type="checkbox">${task}`

  document.getElementById('taskContainer').appendChild(div)
  e.preventDefault();
}

<form id="taskForm">
  <input type="text" id="taskInput" placeholder="Input task" required>
  <input type="submit" value="Add" >
</form>

<div id="taskContainer"></div>

Answer 1

这是我的贡献。

我使用了onchange事件，并用span包裹了整个输入，这得到了一个名为toggled的类.strike-through：

document.getElementById('taskForm').addEventListener('submit', displayTask);

function strikeThrough(e) {
  e.target.parentNode.classList.toggle('strike-through');
}

function displayTask(e) {
  let task = document.getElementById('taskInput').value;
  let div = document.createElement('div');

  div.innerHTML = `<span><input type="checkbox" onchange="strikeThrough(event)">${task}</span>`

  document.getElementById('taskContainer').appendChild(div)
  e.preventDefault();
}

.strike-through {
  text-decoration: line-through;
}

<form id="taskForm">
  <input type="text" id="taskInput" placeholder="Input task" required>
  <input type="submit" value="Add">
</form>

<div id="taskContainer"></div>

Answer 2

这不是最新的技术水平，但是此解决方案仅针对您创建的元素，不会与任何其他输入，复选框或跨度混淆...

document.getElementById('taskForm').addEventListener('submit',displayTask);

var taskId = 0;

function lineThroughTask(checkbox, id){
  if(checkbox.checked){
    document.getElementById('taskCheckbox_' + id).className = "taskLined";
  }else{
    document.getElementById('taskCheckbox_' + id).className = "";
  }
}

function displayTask(e){
  let task = document.getElementById('taskInput').value;
  let div = document.createElement('div');

  div.innerHTML = `<input type="checkbox" onclick="lineThroughTask(this, '` + taskId + `');"><span id="taskCheckbox_` + taskId + `">${task}</span>`;
  
  taskId++;

  document.getElementById('taskContainer').appendChild(div)
  e.preventDefault();
}

.taskLined {
    text-decoration: line-through;
}

<form id="taskForm">
  <input type="text" id="taskInput" placeholder="Input task" required>
  <input type="submit" value="Add" >
</form>

<div id="taskContainer"></div>

Answer 3

您可以使用一个事件侦听器执行此操作，如下所示：

document.getElementById('taskForm').addEventListener('submit', displayTask);

function displayTask(e) {
  let task = document.getElementById('taskInput').value;
  let div = document.createElement('div');

  div.innerHTML = `<input type="checkbox">${task}`

  document.getElementById('taskContainer').appendChild(div)
  e.preventDefault();
}
document.getElementById('taskContainer').addEventListener('click', function(e) {
  if (e.target && e.target.nodeName == 'INPUT' && e.target.type == 'checkbox') {
  
    if (e.target.checked) {
      e.target.parentNode.style.textDecoration = 'line-through';

    } else {
      e.target.parentNode.style.textDecoration = '';
    }
  }
});

<form id="taskForm">
  <input type="text" id="taskInput" placeholder="Input task" required>
  <input type="submit" value="Add">
</form>

<div id="taskContainer"></div>

通过向click添加#taskContainer eventListener来工作。单击#taskContainer时，JS会测试它是否为复选框，如果是，则根据复选框状态添加/删除线槽。

但我认为您应该签出W3school's To Do List。这是一个很好的起点。
W3school的待办事项清单正在运行：

// Create a "close" button and append it to each list item
var myNodelist = document.getElementsByTagName("LI");
var i;
for (i = 0; i < myNodelist.length; i++) {
  var span = document.createElement("SPAN");
  var txt = document.createTextNode("\u00D7");
  span.className = "close";
  span.appendChild(txt);
  myNodelist[i].appendChild(span);
}

// Click on a close button to hide the current list item
var close = document.getElementsByClassName("close");
var i;
for (i = 0; i < close.length; i++) {
  close[i].onclick = function() {
    var div = this.parentElement;
    div.style.display = "none";
  }
}

// Add a "checked" symbol when clicking on a list item
var list = document.querySelector('ul');
list.addEventListener('click', function(ev) {
  if (ev.target.tagName === 'LI') {
    ev.target.classList.toggle('checked');
  }
}, false);

// Create a new list item when clicking on the "Add" button
function newElement() {
  var li = document.createElement("li");
  var inputValue = document.getElementById("myInput").value;
  var t = document.createTextNode(inputValue);
  li.appendChild(t);
  if (inputValue === '') {
    alert("You must write something!");
  } else {
    document.getElementById("myUL").appendChild(li);
  }
  document.getElementById("myInput").value = "";

  var span = document.createElement("SPAN");
  var txt = document.createTextNode("\u00D7");
  span.className = "close";
  span.appendChild(txt);
  li.appendChild(span);

  for (i = 0; i < close.length; i++) {
    close[i].onclick = function() {
      var div = this.parentElement;
      div.style.display = "none";
    }
  }
}

/* Include the padding and border in an element's total width and height */
* {
    box-sizing: border-box;
}

/* Remove margins and padding from the list */
ul {
    margin: 0;
    padding: 0;
}

/* Style the list items */
ul li {
    cursor: pointer;
    position: relative;
    padding: 12px 8px 12px 40px;
    background: #eee;
    font-size: 18px;
    transition: 0.2s;

    /* make the list items unselectable */
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* Set all odd list items to a different color (zebra-stripes) */
ul li:nth-child(odd) {
    background: #f9f9f9;
}

/* Darker background-color on hover */
ul li:hover {
    background: #ddd;
}

/* When clicked on, add a background color and strike out text */
ul li.checked {
    background: #888;
    color: #fff;
    text-decoration: line-through;
}

/* Add a "checked" mark when clicked on */
ul li.checked::before {
    content: '';
    position: absolute;
    border-color: #fff;
    border-style: solid;
    border-width: 0 2px 2px 0;
    top: 10px;
    left: 16px;
    transform: rotate(45deg);
    height: 15px;
    width: 7px;
}

/* Style the close button */
.close {
    position: absolute;
    right: 0;
    top: 0;
    padding: 12px 16px 12px 16px;
}

.close:hover {
    background-color: #f44336;
    color: white;
}

/* Style the header */
.header {
    background-color: #f44336;
    padding: 30px 40px;
    color: white;
    text-align: center;
}

/* Clear floats after the header */
.header:after {
    content: "";
    display: table;
    clear: both;
}

/* Style the input */
input {
    margin: 0;
    border: none;
    border-radius: 0;
    width: 75%;
    padding: 10px;
    float: left;
    font-size: 16px;
}

/* Style the "Add" button */
.addBtn {
    padding: 10px;
    width: 25%;
    background: #d9d9d9;
    color: #555;
    float: left;
    text-align: center;
    font-size: 16px;
    cursor: pointer;
    transition: 0.3s;
    border-radius: 0;
}

.addBtn:hover {
    background-color: #bbb;
}

<div id="myDIV" class="header">
  <h2>My To Do List</h2>
  <input type="text" id="myInput" placeholder="Title...">
  <span onclick="newElement()" class="addBtn">Add</span>
</div>

<ul id="myUL">
  <li>Hit the gym</li>
  <li class="checked">Pay bills</li>
  <li>Meet George</li>
  <li>Buy eggs</li>
  <li>Read a book</li>
  <li>Organize office</li>
</ul>

Answer 4

使用querySelectorAll方法：

var chkBoxes = document.querySelectorAll('input[type=checkbox]');
for (var i = 0, l = chkBoxes.length; i < l; i++) {

    if (chkBoxes[i].checked) {
      ...
    }
}

Answer 5

给他们起一个名字，并找到所有选中的项目：

var checked = document.querySelectorAll('input[name=tasks]:checked');

Answer 6

您可以在元素的classList上使用toggle来切换CSS类。

在这里，在创建div并添加输入后，我们可以获取输入并为其添加事件。在事件内，我们可以切换包含line-through css的父div的类。然后，将在任务中添加/删除一行。

div.querySelector('input').addEventListener('change', e => {
  e.currentTarget.closest('div').classList.toggle('checked', e.currentTarget.checked)
})

这里正在起作用：

document.getElementById('taskForm').addEventListener('submit', displayTask);

function displayTask(e) {
  let task = document.getElementById('taskInput').value;
  let div = document.createElement('div');

  div.innerHTML = `<label><input type="checkbox">${task}</label>`

  div.querySelector('input').addEventListener('change', e => {
    e.currentTarget.closest('div').classList.toggle('checked', e.currentTarget.checked)
  })

  document.getElementById('taskContainer').appendChild(div)
  e.preventDefault();
}

.checked {
  text-decoration: line-through;
}

<form id="taskForm">
  <input type="text" id="taskInput" placeholder="Input task" required>
  <input type="submit" value="Add">
</form>

<div id="taskContainer"></div>

查找所有动态添加的选中复选框

6 个答案: