<canvas id="c" style="border: solid 1px black; width: 300px; height: 300px;"></canvas>
<script type="text/javascript">
var canvas = document.getElementById("c"),
ctx = canvas.getContext("2d");
ctx.fillRect(0, 0, 50, 50);
</script>
导致:
画布无法画出正方形?
小提琴:http://jsfiddle.net/wong2/xZGUj/
可能重复[drawImage方法在画布上在Firefox和其它问题,奇怪的纵横比(http://stackoverflow.com/questions/1931166/ drawimage-on-canvas-has-weird-aspect-in-firefox-and-other-problems) –