使用window.screen怎么样?宽度”?

if (window.screen.width < 800) {
// do something
}

or

if($(window).width() < 800) {
//do something
}

我想这是最好的方法，因为每天都有新的移动设备!

(虽然我认为旧的浏览器不支持它，但试试看吧:))

这取决于用例。所有的移动设备都需要电池。如果你想要的是在不耗尽电池的情况下计算电量，使用电池状态API:

navigator.getBattery().then(battery => {
  battery.charging ? 'charging' : 'not charging';
});

如果您正在寻找的是表示的使用matchMedia，它返回一个布尔值:

if (window.matchMedia("(min-width: 400px)").matches) {
  /* the viewport is at least 400 pixels wide */
} else {
  /* the viewport is less than 400 pixels wide */
}

或者将它们结合起来，在平板设备上获得更好的用户体验。

为了增加额外的控制层，我使用HTML5存储来检测它是使用移动存储还是桌面存储。如果浏览器不支持存储，我有一个移动浏览器名称数组，并将用户代理与数组中的浏览器进行比较。

这很简单。函数如下:

// Used to detect whether the users browser is an mobile browser
function isMobile() {
    ///<summary>Detecting whether the browser is a mobile browser or desktop browser</summary>
    ///<returns>A boolean value indicating whether the browser is a mobile browser or not</returns>

    if (sessionStorage.desktop) // desktop storage 
        return false;
    else if (localStorage.mobile) // mobile storage
        return true;

    // alternative
    var mobile = ['iphone','ipad','android','blackberry','nokia','opera mini','windows mobile','windows phone','iemobile']; 
    for (var i in mobile) if (navigator.userAgent.toLowerCase().indexOf(mobile[i].toLowerCase()) > 0) return true;

    // nothing found.. assume desktop
    return false;
}

  isMobile() {
    if ('maxTouchPoints' in navigator) return navigator.maxTouchPoints > 0;

    const mQ = matchMedia?.('(pointer:coarse)');
    if (mQ?.media === '(pointer:coarse)') return !!mQ.matches;
    
    if ('orientation' in window) return true;
    
    return /\b(BlackBerry|webOS|iPhone|IEMobile)\b/i.test(navigator.userAgent) ||
      /\b(Android|Windows Phone|iPad|iPod)\b/i.test(navigator.userAgent);
  }

导航器。不建议使用userAgent嗅探，因为它不可靠且变化很大。正如您在这里看到的:https://developers.whatismybrowser.com/useragents/explore/导航器。userAgent字符串在同一浏览器的不同版本之间可能有很大差异。

这篇MDN文章可以支持这种说法:https://developer.mozilla.org/en-US/docs/Web/HTTP/Browser_detection_using_the_user_agent#avoiding_user_agent_detection。

上面的答案是对著名的MDN文章中建议的移动检测解决方案的重构。它首先依赖于特性检查，然后作为导航器的最后手段进行回退。userAgent嗅探。

编码快乐!＜3

请注意，现在大多数新一代移动设备的分辨率都大于600x400。例如，一部iPhone 6....

测试证明: 在这里运行最多赞和最近的帖子，有一个可选的检查，像这样运行:

(function(a){
    window.isMobile = (/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows ce|xda|xiino/i.test(a)||/1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(a.substr(0,4)))
})(navigator.userAgent||navigator.vendor||window.opera);

alert("This browser was found to be a % browser.", window.isMobile ? 'mobile' : 'desktop');

不知何故，在以下浏览器应用程序上返回了以下结果。配置:iPhone 6S, iOS 10.3.1。

Safari(最新):将其作为移动设备检测。

Chrome(最新):没有检测到它作为一个移动。

SO, i then tested the suggestion from Lanti (https://stackoverflow.com/a/31864119/7183483), and it did return the proper results (mobile for all iOS devices, and desktop for my Mac). Therefore, i proceeded to edit it a little since it would fire twice (for both mobile and Tablet). I then noticed when testing on an iPad, that it also returned as a mobile, which makes sense, since the Parameters that Lanti uses check the OS more than anything. Therefore, i simply moved the tablet IF statement inside the mobile check, which would return mobile is the Tablet check was negative, and tablet otherwise. I then added the else clause for the mobile check to return as desktop/laptop, since both qualify, but then noticed that the browser detects CPU and OS brand. So i added what is returned in there as part of else if statement instead. To cap it, I added a cautionary else statement in case nothing was detected. See bellow, will update with a test on a Windows 10 PC soon.

哦，我还添加了一个'debugMode'变量，以便在调试和正常编译之间轻松切换。

Dislaimer:这完全是Lanti的功劳，而且这款游戏没有在Windows平板电脑上测试……它可能会返回桌面/笔记本电脑，因为操作系统是纯Windows。等我找到用手机的朋友我会查的。

function userAgentDetect() {
    let debugMode = true;
    if(window.navigator.userAgent.match(/Mobile/i)
        || window.navigator.userAgent.match(/iPhone/i)
        || window.navigator.userAgent.match(/iPod/i)
        || window.navigator.userAgent.match(/IEMobile/i)
        || window.navigator.userAgent.match(/Windows Phone/i)
        || window.navigator.userAgent.match(/Android/i)
        || window.navigator.userAgent.match(/BlackBerry/i)
        || window.navigator.userAgent.match(/webOS/i)) {
        if (window.navigator.userAgent.match(/Tablet/i)
            || window.navigator.userAgent.match(/iPad/i)
            || window.navigator.userAgent.match(/Nexus 7/i)
            || window.navigator.userAgent.match(/Nexus 10/i)
            || window.navigator.userAgent.match(/KFAPWI/i)) {
            window.deviceTypeVar = 'tablet';
            if (debugMode === true) {
                alert('Device is a tablet - ' + navigator.userAgent);
            }
        } else {
            if (debugMode === true) {
                alert('Device is a smartphone - ' + navigator.userAgent);
            };
            window.deviceTypeVar = 'smartphone';
        }
    } else if (window.navigator.userAgent.match(/Intel Mac/i)) {
        if (debugMode === true) {
            alert('Device is a desktop or laptop- ' + navigator.userAgent);
        }
        window.deviceTypeVar = 'desktop_or_laptop';
    } else if (window.navigator.userAgent.match(/Nexus 7/i)
        || window.navigator.userAgent.match(/Nexus 10/i)
        || window.navigator.userAgent.match(/KFAPWI/i)) {
        window.deviceTypeVar = 'tablet';
        if (debugMode === true) {
            alert('Device is a tablet - ' + navigator.userAgent);
        }
    } else {
        if (debugMode === true) {
            alert('Device is unknown- ' + navigator.userAgent);
        }
        window.deviceTypeVar = 'Unknown';
    }
}

以下是我对这个问题的重新思考的解决方案。仍然不完美。唯一真正的解决方案是设备制造商开始认真对待“移动”和“平板”用户代理字符串。

window.onload = userAgentDetect;
function userAgentDetect() {
  if(window.navigator.userAgent.match(/Mobile/i)
  || window.navigator.userAgent.match(/iPhone/i)
  || window.navigator.userAgent.match(/iPod/i)
  || window.navigator.userAgent.match(/IEMobile/i)
  || window.navigator.userAgent.match(/Windows Phone/i)
  || window.navigator.userAgent.match(/Android/i)
  || window.navigator.userAgent.match(/BlackBerry/i)
  || window.navigator.userAgent.match(/webOS/i)) {
    document.body.className += ' mobile';
    alert('True - Mobile - ' + navigator.userAgent);
  } else {
    alert('False - Mobile - ' + navigator.userAgent);
  }
  if(window.navigator.userAgent.match(/Tablet/i)
  || window.navigator.userAgent.match(/iPad/i)
  || window.navigator.userAgent.match(/Nexus 7/i)
  || window.navigator.userAgent.match(/Nexus 10/i)
  || window.navigator.userAgent.match(/KFAPWI/i)) {
    document.body.className -= ' mobile';
    document.body.className += ' tablet';
    alert('True - Tablet - ' + navigator.userAgent);
  } else {
    alert('False - Tablet - ' + navigator.userAgent);
  }
}

当Nexus 7平板电脑只有Android UA字符串时会发生什么?首先，Mobile变成true，之后Tablet也变成true，但是Tablet会从body标签中删除Mobile UA字符串。

CSS:

body.tablet { background-color: green; }
body.mobile { background-color: red; }

为开发添加了警报线。Chrome控制台可以模拟许多手持设备。测试。

编辑:

不要使用这种方法，而是使用特征检测。市场上有如此多的设备和品牌，瞄准一个品牌永远不是正确的解决方案。