我正在尝试创建一个基本的离屏渲染画布示例,但是在js中出现了“无法读取上下文属性”的错误。实际上,我的想法是创建一个像我在https://yalantis.com/看到的演示一样的演示。我想创建我的名字首字母。如果有更好的方法来实现这一点,请 enlighten 我。谢谢,在实际实现之前,这是我的基本尝试 :)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Off Screen Canvas</title>
<script>
function createOffscreenCanvas() {
var offScreenCanvas= document.createElement('canvas');
offScreenCanvas.width= '1360px';
offScreenCanvas.height= '400px';
var context= offScreenCanvas.getContext("2d");
context.fillRect(10,10,200,200);
}
function copyToOnScreen(offScreenCanvas) {
var onScreenContext=document.getElementById('onScreen').getContext('2d');
var offScreenContext=offScreenCanvas.getContext('2d');
var image=offScreenCanvas.getImageData(10,10,200,200);
onScreenContext.putImageData(image,0,0);
}
function main() {
copyToOnScreen(createOffscreenCanvas());
}
</script>
<style>
#onScreen {
width:1360px;
height: 400px;
}
</style>
</head>
<body onload="main()">
<canvas id="onScreen"></canvas>
</body>
</html>