我已經遵循了關於創建畫布的教程,但它不起作用,也沒有繪製矩形。是否有必要在<head>
中擁有腳本?任何幫助,將不勝感激!畫布不顯示
這裏有一個JSFiddle我的代碼。
<!DOCTYPE html>
<html>
<head>
<title>Simple animations in HTML5</title>
</head>
<body>
<h2> Optical Illusion </h2>
<video id="illusion" width="640" height="480" controls>
<source src="Illusion_movie.ogg">
</video>
<div id="buttonbar">
<button onclick="changeSize()">Big/Small</button>
</div>
<p>
Watch the animation for 1 minute, staring at the centre of the image. Then look at something else near you.
For a few seconds everything will appear to distort.
Source: <a href="http://en.wikipedia.org/wiki/File:Illusion_movie.ogg">Wikipedia:Illusion movie</a>
</p>
<script>
var myVideo=document.getElementById("illusion");
var littleSize = false;
function changeSize()
{
myVideo.width = littleSize ? 800 : 400;
littleSize = !littleSize;//toggle boolean
}
</script>
<canvas id= "myCanvas " width= "500 " height= "500 ">
style="border:1px solid #000000;">
</canvas>
<script>
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
context.fillStyle = "blue";
context.fillRect(20, 50, 200, 100);
</script>
</body>
</html>
腳本的「type」屬性在HTML5(OP所使用的)中不是必需的,並且默認爲「text/javascript」 – Ian 2013-05-03 00:30:42
謝謝,想知道爲什麼矩形沒有顯示! – user1554786 2013-05-03 00:34:17
@我不知道,歡呼。 – 2013-05-03 01:08:09