<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script type="text/javascript">
function drawRect() {
var a = document.getElementById("c1");
var context = a.getContext("2d");
context.fillStyle="#FF0000";
context.fillRect(0,0,500,500);
}
function drawLine() {
var b = document.getElementById("c1");
var cont = b.getContext("2d");
cont.moveTo(0,0);
cont.lineTo(50,40);
cont.lineTo(80,50);
cont.stroke();
}
function drawCircle() {
var c = document.getElementById("c1");
var ctx = c.getContext("2d");
ctx.fillStyle="#00ff00";
ctx.beginPath();
ctx.arc(100,100,20,0,Math.PI*2,false);
ctx.closePath();
ctx.fill();
}
function drawGradient() {
var c = document.getElementById("c1");
var context = c.getContext("2d");
var grd = context.createLinearGradient(0,200,500,200);
grd.addColorStop(0,"#ff0000");
grd.addColorStop(1,"#0000ff");
context.fillStyle=grd;
context.fillRect(0,200,500,200);
}
function drawImage() {
var c = document.getElementById("c1");
var context = c.getContext("2d");
var image = new Image();
image.src="asset/a.jpg";
context.drawImage(image,0,0);
}
</script>
</head>
<body>
<button onclick="drawRect()">绘制</button>
<button onclick="drawLine()">画线</button>
<button onclick="drawCircle()">画圆</button>
<button onclick="drawGradient()">画渐变色</button>
<button onclick="drawImage()">画图片</button>
<canvas height="5000" width="5000" id="c1">
Your browser does not support the canvas element.
</canvas>
</body>
</html>
