如何在單擊 javascript 后添加 CSS 並在未單擊時將其刪除

Question

我遇到了一個問題 javascript 點擊更改 CSS

希望點擊的選項的外框和文字點擊后可以加粗，但是沒有選中的不要加粗，試過好幾種寫法，還是不知道怎么完成這個要求，希望能得到大家的幫助。 謝謝你

 let plan = document.querySelector('.plan'); let price = document.querySelector('.price'); let item = document.querySelectorAll('.item'); for (var i = 0; i < item.length; i++) { item[i].addEventListener('click', showplan, false); } function showplan(e) { //Originally intended to increase this way, but it seems that it can't be written like this // e.target.closesst('li').classList.add('bold') // e.target.closesst('h2').classList.add('bold') const planSelected = e.target.closest('li').querySelector('h2'); const priceSelected = e.target.closest('li').querySelector('p'); plan.textContent = planSelected.textContent; price.textContent = priceSelected.textContent; }

 @charset "UTF-8";.product＿list { display: flex; }.product＿list.item { border: 1px solid #ccc; border-radius: 6px; text-align: center; padding: 20px; margin: 20px; }.product＿list.item h2 { margin-bottom: 16px; }.product＿list.item:hover { border: 1px solid #222; }.show { border: 2px solid blue; padding: 20px; }.bold { border: 3px solid; font-weight: 900; }

 <ul class="product＿list"> <li class="item"> <h2>coke</h2> <p>$100</p> </li> <li class="item"> <h2>beef</h2> <p>$600</p> </li> </ul> <h2 class="show">Your food of choice is <span class="plan"></span>The total price is<span class="price"></span></h2>

Answer 1

如何在點擊 javascript 后添加 CSS 並在未點擊時將其刪除？

假設我們有一個類“item”，我們想改變“h1”

add class:
e.currentTarget.classList.add('item')

remove class:
e.currentTarget.classList.remove('item')

toggle class:
e.currentTarget.classList.toggle('item')

切換意味着：（如果 h1 有這個 class，刪除，如果沒有，添加）

Answer 2

您需要切換 class，您可以通過從每個項目中刪除它並僅將其設置為選定的項目來做到這一點：

item.forEach(el => el.classList.remove('active'))
e.currentTarget.classList.add('active')

您還有一個 CSS 特異性問題：

僅使用.bold時， border將被.product＿list.item覆蓋

注意，嘗試使用currentTarget

 const plan = document.querySelector('.plan'); const price = document.querySelector('.price'); const item = document.querySelectorAll('.item'); function showplan(e) { const target = e.currentTarget; const closestLi = target.closest('li'); const planSelected = closestLi.querySelector('h2'); const priceSelected = closestLi.querySelector('p'); item.forEach(el => el.classList.remove('active')) target.classList.add('active') plan.textContent = planSelected.textContent; price.textContent = priceSelected.textContent; } item.forEach(el => el.addEventListener('click', showplan));

 @charset "UTF-8";.product＿list { display: flex; }.product＿list.item { border: 1px solid #ccc; border-radius: 6px; text-align: center; padding: 20px; margin: 20px; }.product＿list.item h2 { margin-bottom: 16px; }.product＿list.item:hover, { border: 1px solid #222; }.product＿list.active { border: 3px solid red; font-weight: 900; color: red; }.show { border: 2px solid blue; padding: 20px; }

 <ul class="product＿list"> <li class="item"> <h2>coke</h2> <p>$100</p> </li> <li class="item"> <h2>beef</h2> <p>$600</p> </li> </ul> <h2 class="show">Your food of choice is <span class="plan"></span>The total price is<span class="price"></span></h2>

Answer 3

使用 jQuery，兩個:radio及其對應的label ：

 var $plan = $('.plan'); var $price = $('.price'); var $item = $('.item'); $('.item').on('click', showplan); function showplan(e) { const plan = $(this).find('h2').text(); const price = $(this).find('p').text(); $plan.text(plan); $price.text(price); }

 @charset "UTF-8";.product＿list { display: flex; }.product＿list.item { border: 1px solid #ccc; border-radius: 6px; text-align: center; padding: 20px; margin: 20px; cursor: pointer; }.product＿list input { display: none; }.product＿list.item h2 { margin-bottom: 16px; }.product＿list.item:hover { border: 1px solid #222; }.show { border: 2px solid blue; padding: 20px; }.product＿list input:checked + label { outline: 2px solid black; /* Prevent jumping. */ border: 1px solid black; font-weight: 900; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="product＿list"> <input type="radio" name="product" id="coke"> <label class="item" for="coke"> <h2>coke</h2> <p>$100</p> </label> <input type="radio" name="product" id="beef"> <label class="item" for="beef"> <h2>beef</h2> <p>$600</p> </label> </div> <h2 class="show">Your food of choice is <span class="plan">?</span>. The total price is <span class="price">?</span>.</h2>