在按钮上使用 addEventListener() 添加 DOM 元素时的奇怪行为

Question

我正在尝试在用户单击按钮时创建包含用户信息的项目卡片。当用户单击新项目按钮时，会弹出一个模态表单，其中包含用户信息和一个创建按钮。每当用户单击创建按钮时，程序应该添加一个新的项目卡。为此，我向 Add new project 按钮和 Create 按钮添加了一个点击事件侦听器。我将创建事件监听器嵌套在添加新项目事件监听器中。这是事件侦听器。

addTileBtn.addEventListener("click", (e) => {
    e.preventDefault();
    modal.style.display = "block";
    const titleField = document.querySelector("#title");
    const descriptionField = document.querySelector("#description");
    const create = document.querySelector("#create");
    const close = document.querySelector("#close");
    create.addEventListener("click", (e) => {
        e.preventDefault();
        title = titleField.value;
        description = descriptionField.value;
        function createProjectTile() {
            const projectTile = document.createElement("div");
            projectTile.classList.add("cards-grid__tile");
            projectTile.textContent = title;
            console.log(title, description);
            return projectTile;
        }
        cardsGrid.appendChild(createProjectTile());
        modal.style.display = "none";
    });
    close.addEventListener("click", (e) => {
        e.preventDefault();
        modal.style.display = "none";
    });
});

问题是当我创建第一张卡片时它工作正常。但是第二次，它创建了两张卡片，第三次创建了三张卡片，依此类推。

这是完整代码的 JSFiddle link。

Answer 1

我已经编辑了你的代码，这应该是你想要的：

const logoutBtn = document.querySelector("#logout");
const addTileBtn = document.querySelector("#add-tile");
const cardsGrid = document.querySelector(".cards-grid");
const modal = document.querySelector(".modal");

const titleField = document.querySelector("#title");
const descriptionField = document.querySelector("#description");
const create = document.querySelector("#create");
const close = document.querySelector("#close");
    
addTileBtn.addEventListener("click", (e) => {
    e.preventDefault();
    modal.style.display = "block";
    titleField.value = "";
    descriptionField.value = "";
});

create.addEventListener("click", (e) => {
  e.preventDefault();
  title = titleField.value;
  description = descriptionField.value;
  function createProjectTile() {
    const projectTile = document.createElement("div");
    projectTile.classList.add("cards-grid__tile");
    projectTile.textContent = title;
    console.log(title, description);
    return projectTile;
  }
  cardsGrid.appendChild(createProjectTile());
  modal.style.display = "none";
});

close.addEventListener("click", (e) => {
  e.preventDefault();
  modal.style.display = "none";
});

:root {
    --main-red: #be3144;
    --main-white: #f0f0f0;
    --main-gray: #303841;
    --main-blue: #45567d;
    --main-blue3: #1c262f;
    --main-blue2: #27333d;
    --main-blue1: #2e3d49;
    --main-light-blue: #02b3e4;
    --main-black: #000000;
    --main-light-black: #3a3d40;
    --main-dark-black: #181719;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html,
body {
    height: 100%;
}

img {
    display: block;
    max-width: 100%;
    height: auto;
}

body {
    font-family: "Poppins", sans-serif;
    font-size: 1.8rem;
    font-weight: 400;
    line-height: 1.4;
    color: var(--main-white);
}

h1,
h2 {
    font-family: "Raleway", sans-serif;
    font-weight: 700;
    text-align: center;
}

h1 {
    font-size: 3.5rem;
}

h2 {
    font-size: 2rem;
    color: var(--main-blue);
    display: block;
}

p {
    font-size: 1.8rem;
    font-weight: 200;
    font-style: italic;
    color: var(--main-white);
}

a {
    text-decoration: none;
    text-align: center;
    display: block;
}

.main {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    height: 100vh;
    background-color: var(--main-white);
}

.box {
    border: none;
    box-shadow: 0 2px 4px rgb(0 0 0 / 10%), 0 8px 16px rgb(0 0 0 / 10%);
    border-radius: 8px;
    background-color: #fff;
}

.box__fields {
    padding: 20px;
}

.box-field {
    margin-bottom: 20px;
    display: flex;
    justify-content: center;
}

.icon {
    position: absolute;
    padding: 10px;
    color: gray;
    min-width: 50px;
    text-align: center;
    font-size: 20px;
    top: 50%;
    transform: translateY(-50%);
}

input,
textarea {
    font-size: 17px;
    padding: 14px 16px;
    width: 300px;
    cursor: text;
    border: 1px solid var(--main-gray);
    border-radius: 6px;
    outline: none;
    padding-left: 45px;
}

.box-btn {
    border: none;
    border-radius: 6px;
    font-size: 20px;
    line-height: 48px;
    padding: 0 16px;
}

.app,
.main-content {
    height: 100%;
}

.title-area {
    background-color: var(--main-blue3);
    width: 100%;
    font-size: 18px;
    min-height: 60px;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    position: fixed;
    top: 0;
    left: 0;
}

.title-area__item {
    padding: 10px 30px;
}

.logout-btn {
    border: none;
    border-radius: 6px;
    font-size: 20px;
    line-height: 30px;
    padding: 0 16px;
    width: 100px;
    cursor: pointer;
    color: #fff;
    background-color: var(--main-light-blue);
}

.logout-btn:hover {
    background-color: #029be4;
}

.content-area {
    margin-top: 60px;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: var(--main-blue);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    grid-gap: 50px;
    margin-bottom: 3rem;
    padding: 5rem 3rem;
}

.cards-grid__tile {
    background-color: var(--main-blue2);
    max-width: 200px;
    padding: 30px;
    text-align: center;
    font-size: 1.2rem;
}

.add-tile-btn {
    border: none;
    border-radius: 6px;
    font-size: 15px;
    line-height: 48px;
    padding: 0 10px;
    cursor: pointer;
    color: #fff;
    background-color: var(--main-light-blue);
}

.modal {
    display: none;
    width: 350px;
    font-size: 1.2rem;
    position: relative;
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    overflow: visible;
}

.box {
    background-color: var(--main-blue1);
    opacity: 0.95;
}

.box-field {
    flex-direction: column;
}

input,
textarea {
    padding: 5px 10px;
    resize: none;
}

.wrapper {
    position: relative;
    text-align: center;
}

.create-btn {
    width: 100px;
    cursor: pointer;
    color: #fff;
    background-color: var(--main-light-blue);
}

.close {
    cursor: pointer;
    position: absolute;
    top: 20px;
    left: 290px;
}

#modal-form {
    position: absolute;
}

.icon {
    color: var(--main-blue3);
}

        <div class="app">
            <div class="nav-wrapper">
                <nav id="nav" class="nav"></nav>
            </div>
            <div class="main-content">
                <div class="title-area">
                    <div class="title-area__item">Menu</div>
                    <div class="title-area__item">Boards</div>
                    <div class="title-area__item">
                        <button id="logout" class="logout-btn btn">
                            Logout
                        </button>
                    </div>
                </div>
                <div class="content-area">
                    <div class="modal">
                        <form id="modal-form" class="box">
                            <a id="close" class="close">
                                <i class="fa fa-times icon">close</i>
                            </a>
                            <div class="box__fields">
                                <div class="box-field">
                                    <label for="title"> Title </label>
                                    <input
                                        id="title"
                                        type="text"
                                        name="title"
                                        required
                                        autofocus
                                    />
                                </div>
                                <div class="box-field">
                                    <label for="description">
                                        Description
                                    </label>
                                    <textarea
                                        id="description"
                                        name="title"
                                        rows="6"
                                        cols="40"
                                    ></textarea>
                                </div>
                                <div class="box-field">
                                    <div class="wrapper">
                                        <button
                                            id="create"
                                            class="create-btn box-btn btn"
                                        >
                                            Create
                                        </button>
                                    </div>
                                </div>
                            </div>
                        </form>
                    </div>
                    <div class="cards-grid">
                        <div class="cards-grid__tile">
                            <button id="add-tile" class="add-tile-btn btn">
                                + Add new project
                            </button>
                        </div>
                    </div>
                </div>
            </div>
        </div>

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