用canvas写一个简易画图工具 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <canvas id="myCanvas" width="800" height="500"
    style="border:1px solid #000000;">您的浏览器不支持canvas
</canvas>
<script type="text/javascript">
    var c =document.querySelector('#myCanvas');
    // 标识画布并指明上下文
    var ctx = c.getContext('2d');

    ctx.strokeStyle = '#000';
    ctx.lineWidth = 3;
    c.onmousedown = function (ev){
        ctx.beginPath();
        ctx.moveTo(ev.clientX,ev.clientY)
        c.onmousemove = function (ev) {
            ctx.lineTo(ev.clientX,ev.clientY);
            ctx.stroke()
        }
        c.onmouseup = function () {
            c.onmousemove = null;
        }
    }
</script>

</body>
</html>

 

posted @ 2019-11-13 09:11  white55k  阅读(844)  评论(2)  编辑  收藏  举报