我正处于项目的开始阶段，我对为什么我的 addEventListener 不起作用感到有些困惑。将 onClick 与提交按钮结合使用确实有效，并且会在控制台中提供输出。但是，当我尝试使其与 addEventListener 一起工作时，它不起作用。
我查看了多个不同的示例，不确定我的 HTML 或 Javascript 中是否存在错误。
<html>
<head>
<title>Loan Payment Estimator</title>
<style>
body {
background-color: #081822;
}
form {
width: 470px; margin: 0px auto;
border:15px solid #eef5ee; background-color: #c1cc9c; font-weight: bold; border-collapse:collapse; padding: 10px; margin-bottom: 0px;
}
form h2 { margin: 0; color: #244769; text-align: center;
}
input {
margin:2px; width:173px;
}
label{
display:inline-block;
width:300px;
margin-right:-180px;
text-align:left;
}
.buttonSubmit {
width: 177px;
margin-left: 124px;
}
</style>
<script>
document.getElementById('submitbtn').addEventListener("click", payment)
function payment() {
principle = document.getElementById('principle').value;
date = document.getElementById('date').value;
length = document.getElementById('loanLength').value;
console.log(principle);
console.log(date);
console.log(length);
}
function calcAPR() {
aprValue = document.getElementById('loanLength').value;
console.log(aprValue);
}
</script>
</head>
<body>
<form>
<h2>Loan Payment Estimator</h2>
<label for="txtPrinciple">Principle:</label>
<input type='text' name='txtPrinciple' id='principle' required>
<br>
<label for="txtDate">Date of Loan:</label>
<input id="date" type="date" style="width:173px" required>
<br>
<label for="txtLength">Length of Loan:</label>
<select style="width:173px" id="loanLength">
<option value="12">12 Months</option>
<option value="24">24 Months</option>
<option value="36">36 Months</option>
<option value="48">48 Months</option>
<option value="60">60 Months</option>
<option value="72">72 Months</option>
<option value="84">84 Months</option>
</select>
<br>
<label for="txtRepayment">Repayment Date:</label>
<input type='text' name='txtRepayment' id="repayment">
<br>
<input type="submit" name="Submit" value="Submit" id="submitbtn" class="buttonSubmit" />
<hr width="100%">
<label for="txtApr">APR:</label>
<input type='text' name='txtApr'>
<br>
<label for="txtInterest">Interest:</label>
<input type='text' name='txtInterest'>
<br>
<label for="txtTotal">Total Paid:</label>
<input type='text' name='txtTotal'>
<hr width="100%">
<h2>Trending</h2>
<div class="row"></div>
<img id="honda" src="2017%20Civic%20Coupe.jpg" width="150" height="110">
<img id="audi" src="2018%20Audi%20A4.jpg" width="150" height="110">
<img id="chevy" src="2018%20Chevy%20Bolt.jpg" width="150" height="110">
<br>
<div class="column">
<img id="subaru" src="2018%20Subaru%20Impreza.jpg" width="150" height="110">
<img id="toyota" src="2018%20Toyota%20Corolla.jpg" width="150" height="110">
<img id="ford" src="2018%20ford%20f-150.jpeg" width="150" height="110">
</div>
</form>
</body>
</html>
感谢您抽出时间来查看。我知道一旦我弄清楚了这一点，我就能完成剩下的事情。
最佳答案
页面尚未加载，因此当您查找元素时，DOM 不会显示该元素的条目。只需等待页面加载即可。
window.onload = function(){
document.getElementById('submitbtn').addEventListener("click", payment);
};
关于javascript - 为什么 addEventListener 对我的提交按钮不起作用？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50204803/