canvas是HTML5的新特性,我们可以用它来轻松地画一个矩形
代码如下:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>用canvas画矩形</title>
<style>
</style>
</head>
<body>
<canvas id="canvas" width="600" height="400"></canvas>
<script type="text/javascript">
function draw(id){
var canvas = document.getElementById(id);
var context = canvas.getContext('2d'); //getContext() 方法可返回一个对象
context.fillStyle = "blue"; // 设置或返回用于填充绘画的颜色、渐变或模式
context.fillRect(50,50,400,300); // x轴 y轴 宽 和 高 ,绘制“被填充”的矩形
}
draw("canvas");
</script>
</body>
</html>
以上代码是有填充的矩形。我们也可以用canvas来画无填充的矩形
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>用canvas画矩形</title>
<style>
</style>
</head>
<body>
<canvas id="canvas" width="600" height="400"></canvas>
<script type="text/javascript">
function draw(id){
var canvas = document.getElementById(id);
var context = canvas.getContext('2d'); //getContext() 方法可返回一个对象
context.strokeStyle = "#000"; //图形边框的填充颜色
context.lineWidth = 5; //用宽度为 5 像素的线条来绘制矩形:
context.strokeRect(50,50,180,120); //绘制矩形(无填充)
context.strokeRect(110,110,180,120);
}
draw("canvas");
</script>
</body>
</html>
程序运行结果: