如何在所有现代浏览器中检测页面缩放级别?

如何在所有现代浏览器中检测页面缩放级别?虽然这篇文章讲述了如何在IE7和IE8中做到这一点，但我找不到一个好的跨浏览器解决方案。 Firefox存储页面缩放级别以供将来访问。在第一页加载，我能得到缩放级别吗?在某个地方，我读到当页面加载后发生缩放变化时，它是有效的。有办法捕捉'缩放'事件吗?

我需要这个，因为我的一些计算是基于像素的，他们可能会在放大时波动。

@tfl给出的修改样本

放大时，此页面会提示不同的高度值。(jsFiddle)

<html>
    <head>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js" type="text/javascript"/></script>
    </head>
    <body>
        <div id="xy" style="border:1px solid #f00; width:100px;">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque sollicitudin tortor in lacus tincidunt volutpat. Integer dignissim imperdiet mollis. Suspendisse quis tortor velit, placerat tempor neque. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Praesent bibendum auctor lorem vitae tempor. Nullam condimentum aliquam elementum. Nullam egestas gravida elementum. Maecenas mattis molestie nisl sit amet vehicula. Donec semper tristique blandit. Vestibulum adipiscing placerat mollis.</div>
        <button onclick="alert($('#xy').height());">Show</button>
    </body>
</html>

当前回答

您的计算仍然是基于一些CSS像素。现在它们在屏幕上的大小不同了。这就是整页缩放的意义所在。

您希望在192dpi设备上的浏览器上发生什么，因此通常在图像中的每个像素中显示四个设备像素?在50%缩放时，这个设备现在在一个设备像素中显示一个图像像素。

2009-12-04 22:32:48

其他回答

这里没有变化!：

<html>
 <head>
  <title></title>
 </head>
<body>
 <div id="xy" style="width:400px;">
  foobar
 </div>
 <div>
  <button onclick="alert(document.getElementById('xy').style.width);">Show</button>
 </div>
</body>
</html>

创建一个简单的HTML文件，点击按钮。不管什么缩放级别:它会显示400px的宽度(至少在firefox和ie8上)

2009-11-12 10:17:54

function supportFullCss3()
{
    var div = document.createElement("div");
    div.style.display = 'flex';
    var s1 = div.style.display == 'flex';
    var s2 = 'perspective' in div.style;

    return (s1 && s2);
};

function getZoomLevel()
{
    var screenPixelRatio = 0, zoomLevel = 0;

    if(window.devicePixelRatio && supportFullCss3())
        screenPixelRatio = window.devicePixelRatio;
    else if(window.screenX == '0')
        screenPixelRatio = (window.outerWidth - 8) / window.innerWidth;
    else
    {
        var scr = window.frames.screen;
        screenPixelRatio = scr.deviceXDPI / scr.systemXDPI;
    }

    //---------------------------------------
    if (screenPixelRatio <= .11){ //screenPixelRatio >= .01 &&
      zoomLevel = "-7";
    } else if (screenPixelRatio <= .25) {
      zoomLevel = "-6";
    }else if (screenPixelRatio <= .33) {
      zoomLevel = "-5.5";
    } else if (screenPixelRatio <= .40) {
      zoomLevel = "-5";
    } else if (screenPixelRatio <= .50) {
      zoomLevel = "-4";
    } else if (screenPixelRatio <= .67) {
      zoomLevel = "-3";
    } else if (screenPixelRatio <= .75) {
      zoomLevel = "-2";
    } else if (screenPixelRatio <= .85) {
      zoomLevel = "-1.5";
    } else if (screenPixelRatio <= .98) {
      zoomLevel = "-1";
    } else if (screenPixelRatio <= 1.03) {
      zoomLevel = "0";
    } else if (screenPixelRatio <= 1.12) {
      zoomLevel = "1";
    } else if (screenPixelRatio <= 1.2) {
      zoomLevel = "1.5";
    } else if (screenPixelRatio <= 1.3) {
      zoomLevel = "2";
    } else if (screenPixelRatio <= 1.4) {
      zoomLevel = "2.5";
    } else if (screenPixelRatio <= 1.5) {
      zoomLevel = "3";
    } else if (screenPixelRatio <= 1.6) {
      zoomLevel = "3.3";
    } else if (screenPixelRatio <= 1.7) {
      zoomLevel = "3.7";
    } else if (screenPixelRatio <= 1.8) {
      zoomLevel = "4";
    } else if (screenPixelRatio <= 1.9) {
      zoomLevel = "4.5";
    } else if (screenPixelRatio <= 2) {
      zoomLevel = "5";
    } else if (screenPixelRatio <= 2.1) {
      zoomLevel = "5.2";
    } else if (screenPixelRatio <= 2.2) {
      zoomLevel = "5.4";
    } else if (screenPixelRatio <= 2.3) {
      zoomLevel = "5.6";
    } else if (screenPixelRatio <= 2.4) {
      zoomLevel = "5.8";
    } else if (screenPixelRatio <= 2.5) {
      zoomLevel = "6";
    } else if (screenPixelRatio <= 2.6) {
      zoomLevel = "6.2";
    } else if (screenPixelRatio <= 2.7) {
      zoomLevel = "6.4";
    } else if (screenPixelRatio <= 2.8) {
      zoomLevel = "6.6";
    } else if (screenPixelRatio <= 2.9) {
      zoomLevel = "6.8";
    } else if (screenPixelRatio <= 3) {
      zoomLevel = "7";
    } else if (screenPixelRatio <= 3.1) {
      zoomLevel = "7.1";
    } else if (screenPixelRatio <= 3.2) {
      zoomLevel = "7.2";
    } else if (screenPixelRatio <= 3.3) {
      zoomLevel = "7.3";
    } else if (screenPixelRatio <= 3.4) {
      zoomLevel = "7.4";
    } else if (screenPixelRatio <= 3.5) {
      zoomLevel = "7.5";
    } else if (screenPixelRatio <= 3.6) {
      zoomLevel = "7.6";
    } else if (screenPixelRatio <= 3.7) {
      zoomLevel = "7.7";
    } else if (screenPixelRatio <= 3.8) {
      zoomLevel = "7.8";
    } else if (screenPixelRatio <= 3.9) {
      zoomLevel = "7.9";
    } else if (screenPixelRatio <= 4) {
      zoomLevel = "8";
    } else if (screenPixelRatio <= 4.1) {
      zoomLevel = "8.1";
    } else if (screenPixelRatio <= 4.2) {
      zoomLevel = "8.2";
    } else if (screenPixelRatio <= 4.3) {
      zoomLevel = "8.3";
    } else if (screenPixelRatio <= 4.4) {
      zoomLevel = "8.4";
    } else if (screenPixelRatio <= 4.5) {
      zoomLevel = "8.5";
    } else if (screenPixelRatio <= 4.6) {
      zoomLevel = "8.6";
    } else if (screenPixelRatio <= 4.7) {
      zoomLevel = "8.7";
    } else if (screenPixelRatio <= 4.8) {
      zoomLevel = "8.8";
    } else if (screenPixelRatio <= 4.9) {
      zoomLevel = "8.9";
    } else if (screenPixelRatio <= 5) {
      zoomLevel = "9";
    }else {
      zoomLevel = "unknown";
    }

    return zoomLevel;
};

2015-09-22 23:30:50

你可以试试

var browserZoomLevel = Math.round(window.devicePixelRatio * 100);

这将给你的浏览器缩放百分比水平在非视网膜显示。对于高DPI/视网膜显示器，它将产生不同的值(例如，Chrome和Safari为200,Firefox为140)。

捕获缩放事件，您可以使用

$(window).resize(function() { 
// your code 
});

2016-06-14 14:34:37

我使用了不同的方法，我创建了一个dom元素，高度和宽度固定为100px，位置固定，不透明度为0，基本上是一个隐藏元素。

然后我使用dom-to-image来捕获这个元素作为图像，这听起来可能有点过分，但我想要一个防弹的解决方案，我们已经在使用这个包了，然后验证输出图像宽度，如果它返回110，缩放是110%，这是非常准确的。

const ORIGINAL_ZOOM_SIZE = 100;
async function isValidateZoomLevel() {
    const base64Render = await domToImage({
      ref: hiddenElementReference,
    });
    const pixleRatio = Math.round(window.devicePixelRatio);
    return new Promise((resolve, reject) => {
      const img = new Image();
      img.onload = () => resolve(ORIGINAL_ZOOM_SIZE === img.width / pixleRatio && ORIGINAL_ZOOM_SIZE === (img.height / pixleRatio));
      img.onerror = reject;
      img.src = base64Render; 
    });
  }

2021-11-09 20:12:38

在移动设备(Chrome for Android或Opera mobile)上，你可以通过window.visualViewport.scale来检测缩放。 https://developer.mozilla.org/en-US/docs/Web/API/Visual_Viewport_API

在Safari上检测:document.documentElement.clientWidth / window。innerWidth(如果设备上没有缩放则返回1)。

2018-06-08 21:27:20

如何在所有现代浏览器中检测页面缩放级别?

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