调整HTML5画布大小以适应窗口

如何自动缩放HTML5 <canvas>元素以适应页面?

例如，我可以得到一个<div>通过设置高度和宽度属性为100%缩放，但一个<canvas>不会缩放，会吗?

当前回答

我使用的是sketch.js，所以在我为画布运行init命令后，我用jquery改变宽度和高度。它将维度基于父元素。

$ (' # DrawCanvas ') .sketch () .attr(“高度”,$ (' # DrawCanvas ') .parent () .height ()) .attr(“宽度”,$ (' # DrawCanvas ') .parent () .width ());

2015-01-06 05:43:04

其他回答

基本上你要做的是将onresize事件绑定到你的body，一旦你捕捉到事件，你只需要使用window调整画布的大小。innerWidth和window.innerHeight。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Canvas Resize</title>

    <script type="text/javascript">
        function resize_canvas(){
            canvas = document.getElementById("canvas");
            if (canvas.width  < window.innerWidth)
            {
                canvas.width  = window.innerWidth;
            }

            if (canvas.height < window.innerHeight)
            {
                canvas.height = window.innerHeight;
            }
        }
    </script>
</head>

<body onresize="resize_canvas()">
        <canvas id="canvas">Your browser doesn't support canvas</canvas>
</body>
</html>

2011-09-08 22:18:59

这对我很管用。伪代码:

// screen width and height
scr = {w:document.documentElement.clientWidth,h:document.documentElement.clientHeight}
canvas.width = scr.w
canvas.height = scr.h

另外，就像devyn说的，您可以替换“document.documentElement”。宽度和高度均为“inner”的客户端:

**document.documentElement.client**Width
**inner**Width
**document.documentElement.client**Height
**inner**Height

它仍然有效。

2020-10-24 17:08:50

我相信我已经找到了一个优雅的解决方案:

JavaScript

/* important! for alignment, you should make things
 * relative to the canvas' current width/height.
 */
function draw() {
  var ctx = (a canvas context);
  ctx.canvas.width  = window.innerWidth;
  ctx.canvas.height = window.innerHeight;
  //...drawing code...
}

CSS

html, body {
  width:  100%;
  height: 100%;
  margin: 0;
}

到目前为止，还没有对我的表现产生任何大的负面影响。

2010-06-20 06:43:09

CSS

body { margin: 0; } 
canvas { display: block; }

JavaScript

window.addEventListener("load", function()
{
    var canvas = document.createElement('canvas'); document.body.appendChild(canvas);
    var context = canvas.getContext('2d');

    function draw()
    {
        context.clearRect(0, 0, canvas.width, canvas.height);
        context.beginPath();
        context.moveTo(0, 0); context.lineTo(canvas.width, canvas.height); 
        context.moveTo(canvas.width, 0); context.lineTo(0, canvas.height); 
        context.stroke();
    }
    function resize()
    {
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;
        draw();
    }
    window.addEventListener("resize", resize);
    resize();
});

2014-11-28 16:39:05

一个纯CSS的方法添加到解决方案@jerseyboy上面。适用于Firefox (v29测试)，Chrome (v34测试)和Internet Explorer (v11测试)。

<!DOCTYPE html>
<html>
    <head>
    <style>
        html,
        body {
            width: 100%;
            height: 100%;
            margin: 0;
        }
        canvas {
            background-color: #ccc;
            display: block;
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            width: 100%;
            height: 100%;
        }
    </style>
</head>
<body>
    <canvas id="canvas" width="500" height="500"></canvas>
    <script>
        var canvas = document.getElementById('canvas');
        if (canvas.getContext) {
            var ctx = canvas.getContext('2d');
            ctx.fillRect(25,25,100,100);
            ctx.clearRect(45,45,60,60);
            ctx.strokeRect(50,50,50,50);
        }
    </script>
</body>
</html>

链接到示例:http://temporaer.net/open/so/140502_canvas-fit-to-window.html

但要小心，正如@jerseyboy在他的评论中所说:

用CSS重新缩放画布是很麻烦的。至少在Chrome和 Safari中，鼠标/触摸事件的位置不会1:1对应 Canvas像素位置，你需要变换坐标系统。

2014-05-02 18:51:41

调整HTML5画布大小以适应窗口

推荐文章

最新文章

标签