我已经尝试查看与错误相关的已回答问题：
TypeError: document.getElementById('myChart').getContext is not a function. (In 'document.getElementById('myChart').getContext('2d')', 'document.getElementById('myChart').getContext' is undefined)
但是到目前为止还没有给我任何建议。我正在尝试使用chart.js库，并不断在标题中出现错误。下面是我的HTML和javascript代码，js代码在一个名为app.js的单独文件中。如有任何帮助，我们将不胜感激。谢谢
<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.jsdelivr.net/npm/chart.js@2.9.4/dist/Chart.min.js"></script>
<title></title>
<link rel="stylesheet" type="text/css" href="contxt.css" />
</head>
<body>
<div class="container">
<div id='myChart'></div>
</div>
</body>
<script src="app.js"></script>
</html>
这是JS:
if (document.readyState == 'loading') {
document.addEventListener('DOMContentLoaded', fire)
}else{
fire()
}
function fire() {
var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
'rgba(255, 99, 132, 0.2)',
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(75, 192, 192, 0.2)',
'rgba(153, 102, 255, 0.2)',
'rgba(255, 159, 64, 0.2)'
],
borderColor: [
'rgba(255, 99, 132, 1)',
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(75, 192, 192, 1)',
'rgba(153, 102, 255, 1)',
'rgba(255, 159, 64, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
}
只有画布才能有上下文。请更改
<div class="container">
<div id='myChart'></div>
</div>
对于
<div class="container">
<canvas id='myChart'></canvas> <!-- this line -->
</div>