<canvas id="myCanvas" width="200" height="200" style="border:1px solid"> 您的浏览器不支持 HTML5 canvas 标签。 </canvas> <br> <script> var c=document.getElementById("myCanvas"); var ctx=c.getContext("2d"); ctx.fillStyle="#92B901"; ctx.fillRect(50,50,100,100); function clearCanvas() { c.height=300; } </script> <button onclick="clearCanvas()">Clear canvas</button>