html5入門

<canvas id="canvassample1" width="140" height="140"></canvas> <script type="text/javascript"> onload = function() { draw1(); }; function draw1() { var canvas = document.getElementById('canvassample1'); if ( ! canvas || ! canvas.getContext ) { return false; } var ctx = canvas.getContext('2d'); ctx.beginPath(); ctx.moveTo(20, 20); ctx.lineTo(120, 20); ctx.lineTo(120, 120); ctx.lineTo(20, 120); ctx.c