我编写了一个jQuery插件,可以在桌面和移动设备上使用。我想知道是否有一种方法可以用JavaScript来检测设备是否具有触摸屏功能。我使用jquery-mobile.js来检测触摸屏事件,它适用于iOS, Android等,但我也想根据用户的设备是否有触摸屏来编写条件语句。

这可能吗?


当前回答

事实上,我研究了这个问题并考虑了各种情况。因为这在我的项目中也是一个大问题。所以我达到了下面的功能,它适用于所有设备上所有浏览器的所有版本:

const isTouchDevice = () => {
  const prefixes = ['', '-webkit-', '-moz-', '-o-', '-ms-', ''];
  const mq = query => window.matchMedia(query).matches;

  if (
    'ontouchstart' in window ||
    (window.DocumentTouch && document instanceof DocumentTouch)
  ) {
    return true;
  }
  return mq(['(', prefixes.join('touch-enabled),('), 'heartz', ')'].join(''));
};

提示:显然,isTouchDevice只返回布尔值。

其他回答

这种方法对我来说很有效,它等待第一次用户交互,以确保他们是在触摸设备上

var touchEnabled = false;
$(document.body).one('touchstart',
    function(e){
        touchEnabled=true;
        $(document.documentElement).addClass("touch");
        // other touch related init 
        //
    }
);

看看这篇文章,它给出了一个非常好的代码片段,告诉你当检测到触摸设备时该怎么做,或者如果touchstart事件被调用了该怎么做:

$(function(){
  if(window.Touch) {
    touch_detect.auto_detected();
  } else {
    document.ontouchstart = touch_detect.surface;
  }
}); // End loaded jQuery
var touch_detect = {
  auto_detected: function(event){
    /* add everything you want to do onLoad here (eg. activating hover controls) */
    alert('this was auto detected');
    activateTouchArea();
  },
  surface: function(event){
    /* add everything you want to do ontouchstart here (eg. drag & drop) - you can fire this in both places */
    alert('this was detected by touching');
    activateTouchArea();
  }
}; // touch_detect
function activateTouchArea(){
  /* make sure our screen doesn't scroll when we move the "touchable area" */
  var element = document.getElementById('element_id');
  element.addEventListener("touchstart", touchStart, false);
}
function touchStart(event) {
  /* modularize preventing the default behavior so we can use it again */
  event.preventDefault();
}

这个问题

由于混合设备使用触摸和鼠标输入的组合,你需要能够动态地改变状态/变量,控制一段代码是否应该运行,如果用户是触摸用户或不是。

触控设备也可以在点击时触发鼠标移动。

解决方案

Assume touch is false on load. Wait until a touchstart event is fired, then set it to true. If touchstart was fired, add a mousemove handler. If the time between two mousemove events firing was less than 20ms, assume they are using a mouse as input. Remove the event as it's no longer needed and mousemove is an expensive event for mouse devices. As soon as touchstart is fired again (user went back to using touch), the variable is set back to true. And repeat the process so it's determined in a dynamic fashion. If by some miracle mousemove gets fired twice on touch absurdly quickly (in my testing it's virtually impossible to do it within 20ms), the next touchstart will set it back to true.

在Safari iOS和Chrome for Android上进行了测试。

注意:不是100%确定的指针事件为MS Surface等。

Codepen演示


const supportsTouch = 'ontouchstart' in window;
let isUsingTouch = false;

// `touchstart`, `pointerdown`
const touchHandler = () => {
  isUsingTouch = true;
  document.addEventListener('mousemove', mousemoveHandler);
};

// use a simple closure to store previous time as internal state
const mousemoveHandler = (() => {
  let time;
  
  return () => {
    const now = performance.now();

    if (now - time < 20) {
      isUsingTouch = false;
      document.removeEventListener('mousemove', mousemoveHandler);
    }

    time = now;
  }
})();

// add listeners
if (supportsTouch) {
  document.addEventListener('touchstart', touchHandler);
} else if (navigator.maxTouchPoints || navigator.msMaxTouchPoints) {
  document.addEventListener('pointerdown', touchHandler);
}

工作小提琴

我是这样做到的;

function isTouchDevice(){
    return true == ("ontouchstart" in window || window.DocumentTouch && document instanceof DocumentTouch);
}

if(isTouchDevice()===true) {
    alert('Touch Device'); //your logic for touch device
}
else {
    alert('Not a Touch Device'); //your logic for non touch device
}

更新2021

要查看以前的答案,请查看历史记录。我决定从头开始,因为在保存历史的时候,它变得难以控制。

我最初的回答是,使用与Modernizr使用的相同功能可能是一个好主意,但这不再有效,因为他们删除了这个PR: https://github.com/Modernizr/Modernizr/pull/2432上的“touchevents”测试,因为这是一个令人困惑的主题。

话虽如此,这应该是一个相当好的检测浏览器是否具有“触摸功能”的方法:

function isTouchDevice() {
  return (('ontouchstart' in window) ||
     (navigator.maxTouchPoints > 0) ||
     (navigator.msMaxTouchPoints > 0));
}

但是对于比我更聪明的人写过的更高级的用例,我建议阅读这些文章:

斯图·考克斯:你无法检测触摸屏 触摸检测:它是“为什么”,而不是“如何” Patrick H. Lauke的敏感演讲