51help TIY
码：
<!DOCTYPE html> <html> <body> <canvas id="myCanvas" width="200" height="200" style="border:1px solid"> Your browser does not support the canvas element. </canvas> <script type="text/javascript"> var c=document.getElementById("myCanvas"); var cxt=c.getContext("2d"); cxt.fillStyle="#92B901"; cxt.fillRect(50,50,100,100); function clearCanvas() { c.height=c.height; } </script> <br /> <button onclick="clearCanvas()">清空画布</button> </body> </html>
查看结果: