要缩放HTML5 Canvas，我们可以使用scale（）转换方法来缩放画布上下文的x和y组件。
html代码：
<!DOCTYPE HTML>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
</style>
</head>
<body>
<canvas id="myCanvas" width="578" height="200"></canvas>
<script>
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
var rectWidth = 150;
var rectHeight = 75;
// translate context to center of canvas
context.translate(canvas.width / 2, canvas.height / 2);
// scale y component
context.scale(1, 0.5);
context.fillStyle = 'blue';
context.fillRect(rectWidth / -2, rectHeight / -2, rectWidth, rectHeight);
</script>
</body>
</html>
1230博客
热门推荐：