为了始终使画布全屏显示宽度和高度，这意味着即使调整了浏览器的大小，也需要在将画布调整为window.innerHeight和window.innerWidth的函数中运行绘制循环。

HTML

<canvas id="canvas"></canvas>

JavaScript

(function() {
    var canvas = document.getElementById('canvas'),
            context = canvas.getContext('2d');

    // resize the canvas to fill browser window dynamically
    window.addEventListener('resize', resizeCanvas, false);

    function resizeCanvas() {
            canvas.width = window.innerWidth;
            canvas.height = window.innerHeight;

            /**
             * Your drawings need to be inside this function otherwise they will be reset when 
             * you resize the browser window and the canvas goes will be cleared.
             */
            drawStuff(); 
    }
    resizeCanvas();

    function drawStuff() {
            // do your drawing stuff here
    }
})();

CSS

* { margin:0; padding:0; } /* to remove the top and left whitespace */

html, body { width:100%; height:100%; } /* just to be sure these are full screen*/

canvas { display:block; } /* To remove the scrollbars */

这样可以正确地使画布达到浏览器的整个宽度和高度。您只需要在drawStuff（）函数中将所有用于绘制的代码放到画布上即可。