利用html5的canvas元素使用 JavaScript 在网页上绘制图像。
通过规定尺寸、颜色和位置,来绘制一个圆:
<!DOCTYPE htma> <html> <body> <canvas id="myCanvas" width="200" height="100" style="border:1px solid #3CF;"> Your browser does not support the canvers element. </canvas> <script type="text/javascript"> var c=document.getElementById("myCanvas"); var cxt=c.getContext("2d"); cxt.fillStyle="#3CF"; cxt.beginPath(); cxt.arc(70,18,15,0,Math.PI*2,true); cxt.closePath(); cxt.fill(); </script> </body> </html>
<!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"); cxt.moveTo(10,10); cxt.lineTo(150,50); cxt.lineTo(10,50); cxt.stroke(); </script> </body> </html>
<!DOCTYPE htma> <html> <body> <canvas id="myCanvas" width="200" height="100" style="border:4px solid #3CF;"> Your browser does not support the canvers element. </canvas> <script type="text/javascript"> var c=document.getElementById("myCanvas"); 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> </body> </html>
<!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>