HTML5画布(基础篇11-10)

 1 <script type="text/javascript">
 2     $(function(){
 3         var s = $("#myCanvas")[0];
 4         var canvas = s.getContext("2d");
 5         //画直线
 6         canvas.strokeStyle = "#FF0000";
 7         canvas.moveTo(100,100);
 8         canvas.lineTo(300,400);
 9         canvas.stroke();
10         canvas.beginPath();
11         canvas.moveTo(100,100);
12         canvas.lineTo(400,300);
13         canvas.stroke();
14     //2、画矩形
15         var c = s.getContext("2d");
16         //填充颜色
17         c.fillStyle="blue";
18         c.beginPath();
19         //方式一(填充)
20         c.fillRect(10,10,30,30);
21         c.beginPath();
22         //方式二(填充)
23         c.rect(300,300,100,100);
24         c.fill();
25         c.beginPath();
26         //线条颜色
27         c.strokeStyle="yellow";
28         c.strokeRect(50,50,30,30);
29     //3、画圆
30         c.beginPath();
31         //线条宽度
32         c.lineWidth = 3;
33         //线条颜色
34         c.strokeStyle="black";
35         // 参数:  x,y,r,开始弧度,结束弧度,顺逆时针
36         c.arc(200,200,30,0,360*Math.PI/180,false);
37         //空心元
38         c.stroke();
39         //实心圆
40         c.fill();
41     //4、html5没有提供画圆角矩形API 但是通过arcTo方法可以实现这个效果
42         c.beginPath();
43         c.moveTo(200,200);
44         c.lineTo(250,200);
45         c.arcTo(300,200,300,250,30);
46         c.lineTo(300,300);
47         c.stroke();
48         
49     });
50 </script>

对于画圆角矩形而言:arcTo()的5个参数分别代表 A点的坐标 B的坐标 以及半径

posted on 2014-11-10 21:52  欲上云端  阅读(235)  评论(0编辑  收藏  举报