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  • h5-画板

     1 <!DOCTYPE html>
     2 <html lang="en">
     3 <head>
     4     <meta charset="UTF-8">
     5     <title>Title</title>
     6     <style>
     7         *
     8         {
     9             margin: 0;
    10             padding: 0;
    11         }
    12         #box
    13         {
    14             width: 600px;
    15             height: 600px;
    16             margin: 0 auto;
    17         }
    18         #ca
    19         {
    20 
    21             background: #ccc;
    22         }
    23     </style>
    24 </head>
    25 <body>
    26 <div id="box">
    27     <canvas id="ca" width="600" height="600">
    28 
    29     </canvas>
    30 </div>
    31 
    32 <script >
    33     var box=document.getElementById('box');
    34     var ca=document.getElementById('ca');
    35     var ctx=ca.getContext('2d');
    36     ca.onmousedown=function (ev) {
    37         var event=window.event||ev;
    38         var startx=event.clientX-box.offsetLeft;
    39         var starty=event.clientY-box.offsetTop;
    40         ctx.beginPath();
    41         ctx.moveTo(startx,starty);
    42         ca.onmousemove=function (ev) {
    43             var event=window.event||ev;
    44             var endx=event.clientX-box.offsetLeft;
    45             var endy=event.clientY-box.offsetTop;
    46             ctx.lineTo(endx,endy);
    47             ctx.strokeStyle='green';
    48             ctx.stroke();
    49         }
    50         document.onmouseup=function () {
    51             ca.onmousemove=null;
    52             ctx.closePath();
    53         }
    54     }
    55 </script>
    56 </body>
    57 </html>
    index.html

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  • 原文地址:https://www.cnblogs.com/yoyoyoyoyoyo/p/5997607.html
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