复选框:如果选中复选框，则启用按钮

Question

在我的页面中有一个模态窗口，在模态中我有 2 个复选框，我希望如果选中所有复选框都启用发送按钮并更改背景颜色(如果禁用 bgcolor 是灰色，否则 bgcolor 红色(。我怎么能正确呢？

.HTML：

<form action="" method="POST" class="send-modal-data">
<input type="text" id="send_email" name="subscribe-email" class="modal-input" placeholder="Email *" required="required">
<div class="checkboks custom-sq vdc-cb-area">
<input type="checkbox" id="box4" name="vdc-modal-cb" class="checked-checkbox"/>
<label for="box4" class="checkboks-text d-flex align-center"><?php echo the_field('vdc_checkbox_txt', 'option'); ?></label>
</div>
<div class="checkboks custom-sq vdc-cb-area">
<input type="checkbox" id="box7" name="vdc-modal-cb" class="checked-checkbox" />
<label for="box7" class="checkboks-text d-flex align-center"><?php echo the_field('vdc_checkbox_text_2', 'option'); ?></label>
</div>
<div class="success-msg">
<div class="msg"></div>
</div>
<input type="submit" name="subscribe-form" id="vdc-send-modal" class="danger-btn send-subscribe" disabled="disabled" value="<?php echo the_field('lets_get_started', 'option'); ?>"></input>
</form>

.JS：

var checks = document.getElementsByName('vdc-modal-cb');
var checkBoxList = document.getElementById('vdc-cb-area');
var sendbtn = document.getElementById('vdc-send-modal');
function allTrue(nodeList) {
for (var i = 0; i < nodeList.length; i++) {
if (nodeList[i].checked === false) return false;
}
return true;
}
checkBoxList.addEventListener('click', function(event) {
sendbtn.disabled = true;
if (allTrue(checks)) sendbtn.disabled = false;
console.log(123);
});

注意：我从堆栈溢出中获取了此示例，但它对我不起作用

Answer 1

1.你应该使用getElementsByClassName来获取具有相同类的元素。

2.To 将 eventListener 添加到类元素，则应遍历这些元素。

var checks = document.getElementsByName('vdc-modal-cb');
var checkBoxList = document.getElementsByClassName('vdc-cb-area');
var sendbtn = document.getElementById('vdc-send-modal');
function allTrue(nodeList) {
for (var i = 0; i < nodeList.length; i++) {
if (nodeList[i].checked === false) return false;
}
return true;
}
for (var i = 0; i < checkBoxList.length; i++) {
checkBoxList[i].addEventListener('click', function(event) {
sendbtn.disabled = true;
if (allTrue(checks)) sendbtn.disabled = false;
});
}