canvas.getContext（“2d”）未定义 [英] canvas.getContext("2d") is undefined
本文介绍了canvas.getContext（“2d”）未定义的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
下面的代码在所有浏览器都打开，但是当我试图运行WPF Web浏览器控件中的代码，它给出一个Javascript错误canvas.getContext（2d）未定义。
The below code opens fine in all browsers, but when I'm trying to run the code in WPF web browser control, it gives a Javascript error "canvas.getContext("2d") is undefined".
<html>
<head>
<title>Bar Chart</title>
<script src="Chart.js" type="text/javascript"></script>
<script type="text/javascript">
var canvas = null;
var context = null;
window.onload = function () {
invokeService();
canvas = document.getElementById("canvas");
var context = canvas.getContext("2d");
alert(context);
var myLine = new Chart(document.getElementById("canvas").getContext("2d")).Bar(barChartData);
};
var barChartData;
function invokeService() {
alert("q");
barChartData = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [
{
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,1)",
data: [65, 59, 90, 81, 56, 55, 40]
},
{
fillColor: "rgba(151,187,205,0.5)",
strokeColor: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 96, 27, 100]
}
]
}
}
</script>
</head>
<body>
<canvas id="canvas" height="450" width="600"></canvas>
</body>
</html>
编辑1：可以在此下载chart.js https://github.com/nnnick/Chart.js
Edit 1: chart.js can be download for here https://github.com/nnnick/Chart.js
推荐答案
在一杯咖啡后，我通过添加以下行解决了这个问题。
After one cup of coffee I have solved that issue by adding following line
<meta http-equiv="X-UA-Compatible" content="IE=9">
这篇关于canvas.getContext（“2d”）未定义的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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