HTML5 Canvas clearRect()方法清除画布
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canvas
要清除HTML5 Canvas,我们可以使用clearRect()方法清除画布位图。 这比清除画布的其他技术要好得多,例如重置画布宽度和高度,或者破坏canvas元素然后重新创建它。
说明:单击清除按钮以清除画布
html代码:
<!DOCTYPE HTML> <html> <head> <style> body { margin: 0px; padding: 0px; } #buttons { position: absolute; top: 5px; left: 10px; } #buttons > input { padding: 10px; display: block; margin-top: 5px; } </style> </head> <body> <canvas></canvas> <div> <input type="button" value="Clear"> </div> <script> var canvas = document.getElementById('myCanvas'); var context = canvas.getContext('2d'); // begin custom shape context.beginPath(); context.moveTo(170, 80); context.bezierCurveTo(130, 100, 130, 150, 230, 150); context.bezierCurveTo(250, 180, 320, 180, 340, 150); context.bezierCurveTo(420, 150, 420, 120, 390, 100); context.bezierCurveTo(430, 40, 370, 30, 340, 50); context.bezierCurveTo(320, 5, 250, 20, 250, 50); context.bezierCurveTo(200, 5, 150, 20, 170, 80); // complete custom shape context.closePath(); context.lineWidth = 5; context.strokeStyle = 'blue'; context.stroke(); // bind event handler to clear button document.getElementById('clear').addEventListener('click', function() { context.clearRect(0, 0, canvas.width, canvas.height); }, false); </script> </body> </html>