您的位置:首页 > Web前端 > HTML5

HTML5移动开发极速快三平台出租之路——Canvas图形绘制基础

2018-03-27 10:11 393 查看
在前面提到Canvas是HTML5中一个重要特点,canvas功能非常强大,用photoshop可以实现的效果canvas也同样可以实现,下面我们用canvas实现基本图形的绘制。极速快三平台出租Q1446595067 vx:HZYM2018 论坛:haozi-bbs.com一、Canvas标签的使用 <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="1" width="200" height="200" style="border:1px solid red"></canvas>
</body>
</html>


 可以看到Canvas就像一块画布,我们可以在这个画布上面绘制我们需要的图形。canvas 元素本身是没有绘图能力的。所有的绘制工作必须在 JavaScript 内部完成。二、画矩形 <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="1" width="500" height="500" style="border:1px solid red" onmousemove="mousexy(envent)"></canvas>
</body>
<script type="text/javascript">
var c=document.getElementById('1');
var p=c.getContext("2d");
//getContext("2d") 对象是内建的 HTML5 对象,拥有多种绘制路径、矩形、圆形、字符以及添加图像的方法。
p.fillStyle="#FF0000";
p.fillRect(0, 0, 300, 300);
p.fillStyle="rgba(0,0,255,0.5)";
p.fillRect(200,200,500,500);
</script>
</html>


 三、画线条 <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="1" width="200" height="200" style="border:1px solid red" onmousemove="mousexy(envent)"></canvas>
</body>
<script type="text/javascript">
var c=document.getElementById('1');
var p=c.getContext("2d");

p.moveTo(10,10);
p.lineTo(150,50);
p.lineTo(10,50);
p.stroke();
</script>
</html>


 四、画圆形 <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="1" width="200" height="200" style="border:1px solid red" onmousemove="mousexy(envent)"></canvas>
</body>
<script type="text/javascript">
var c=document.getElementById('1');
var p=c.getContext("2d");

p.fillStyle="#FF0000";
p.beginPath();
p.arc(80,80,15,0,Math.PI*2,true);
p.closePath();
p.fill();
</script>
</html>


 五、渐变 <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="1" width="200" height="200" style="border:1px solid red" onmousemove="mousexy(envent)"></canvas>
</body>
<script type="text/javascript">
var c=document.getElementById("1");
var cxt=c.getContext("2d");
var grd=cxt.createLinearGradient(0,0,175,50);
grd.addColorStop(0,"#FF0000");
grd.addColorStop(1,"#00FF00");
cxt.fillStyle=grd;
cxt.fillRect(0,0,175,50);
</script>
</html>


 六、绘制图片 <!DOCTYPE HTML>
<html>
<body>

<canvas id="myCanvas" width="200" height="100" style="border:1px solid #c3c3c3;">
Your browser does not support the canvas element.
</canvas>

<script type="text/javascript">

var c=document.getElementById("myCanvas");
var cxt=c.getContext("2d");
var img=new Image()
img.src="/i/eg_flower.png"
cxt.drawImage(img,0,0);

</script>

</body>
</html>


 七、多边形 <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="1" width="200" height="200" style="border:1px solid red" onmousemove="mousexy(envent)"></canvas>
</body>
<script type="text/javascript">
var c=document.getElementById('1');
var p=c.getContext("2d");

p.fillStyle="#FF0000";
p.moveTo(10,10);
p.lineTo(150,50);
p.lineTo(10,50);
p.lineTo(20,30);
p.fill();
</script>
</html>
内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理 点击这里给我发消息
标签: