【发布时间】：2020-12-24 10:47:27
【问题描述】：
我正在构建一个待办事项应用程序，一切都运行良好，直到我决定添加一个按钮以一键删除所有待办事项（ul）。当我单击删除按钮时，所有待办事项都会被删除，但是当我单击添加按钮时，它们都会立即返回。
const input = document.getElementById('input');
const addBtn = document.getElementById('btn');
const removeBtn = document.getElementById('removeBtn')
const todoList = document.getElementById('todoList');
var ulElement = document.createElement('ul');
let placeholderValue = '';
// This code is for clear placeholder value
input.addEventListener('focus' , () => {
placeholderValue = input.placeholder;
input.placeholder = '';
});
input.addEventListener('blur' , ()=> {
input.placeholder = placeholderValue;
});
// this function is for add to do to a list
function addTodo(){
let liElements = document.createElement('li');
todoList.appendChild(ulElement);
ulElement.appendChild(liElements);
liElements.classList.add('liElement')
liElements.innerHTML = input.value;
// this code is for remove todo from the list
liElements.addEventListener('contextmenu' , (e)=> {
e.preventDefault();
liElements.classList.add('done');
});
liElements.addEventListener('dblclick' , (e) => {
e.preventDefault()
liElements.remove()
});
};
addBtn.addEventListener('click' , addTodo)
removeBtn.addEventListener('click' , () => {
ulElement.remove()
});@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@1,600&display=swap');
*{
margin: 0;
box-sizing: border-box;
font-family: 'Playfair Display', serif;
}
body{
background-color: #DC86A9;
}
.mainInput {
display: flex;
justify-content: center;
margin-top: 15%;
}
.mainInput input + button {
margin-left: 10px;
}
.mainInput input {
width: 500px;
height: 50px;
border: none;
border-radius: 50px;
box-shadow: 4px 4px 60px white;
padding: 25px;
}
.mainInput input::placeholder{
font-size: 22px;
text-align: center;
}
.mainInput button {
border-radius: 10px ;
background-color: rgb(102, 102, 255);
margin-left: 10px;
border: none;
border-radius: 550px;
color: white;
font-weight: 900;
font-size: 32px;
width: 80px;
cursor: pointer;
box-shadow: 4px 4px 30px white;
}
.btn1 {
font-size: 14px !important;
background-color: rgb(252, 53, 53) !important;
padding-left: 5px;
}
span {
display: flex;
justify-content: center;
margin-top: 50px;
font-size: 30px;
color: white;
}
.todoList {
display:flex;
justify-content:center;
margin-top : 2%;
}
.todoList ul {
list-style-type: none;
margin-right: 30px;
color: white;
font-size: 26px;
font-weight: 500
}
.todoList ul li {
cursor: pointer;
}
.done {
color: rgb(190, 190, 190);
text-decoration: line-through
}
.note {
display: flex;
justify-content: center;
margin-top: 10px;
font-size: 14px;
color: white;
}<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="css/style.css">
<title>TodoApp</title>
</head>
<body>
<div class="mainInput">
<input type="text" class="input" id="input" placeholder="Enter your todo : ">
<button class="btn" id="btn">+</button><button class="btn btn1" id="removeBtn">RemoveAll</button>
</div>
<span> Todo list : </span>
<div class="todoList" id="todoList"></div>
<span class="note">Right click to make todo done</span>
<span class="note">dbl click to remove todo</span>
<script src="js/main.js"></script>
<script src="https://kit.fontawesome.com/a81368914c.js"></script>
</body>
</html>【问题讨论】：
-
您正在从 DOM 中删除 uElement 但并未删除其子元素，因此当 ulElement 在 addTodo() 函数中重新附加到 DOM 时，它们自然会重新出现。
-
哦！我现在明白了，谢谢
标签： javascript html css