如何检测用户用JavaScript在网页上向某个方向滑动手指?

我想知道是否有一种解决方案可以同时适用于iPhone和Android手机上的网站。


当前回答

我遇到了触摸端处理程序连续发射的问题,而用户正在拖着一个手指。我不知道这是不是因为我做错了什么但是我重新连接了这个用touchmove来累积移动touchend实际上触发了回调。

我还需要大量这样的实例,所以我添加了启用/禁用方法。

还有一个阈值,短刷不会触发。每次Touchstart 0的计数器。

您可以动态地更改target_node。创建时启用是可选选项。

/** Usage: */
touchevent = new Modules.TouchEventClass(callback, target_node);
touchevent.enable();
touchevent.disable();

/** 
*
*   Touch event module
*
*   @param method   set_target_mode
*   @param method   __touchstart
*   @param method   __touchmove
*   @param method   __touchend
*   @param method   enable
*   @param method   disable
*   @param function callback
*   @param node     target_node
*/
Modules.TouchEventClass = class {

    constructor(callback, target_node, enable=false) {

        /** callback function */
        this.callback = callback;

        this.xdown = null;
        this.ydown = null;
        this.enabled = false;
        this.target_node = null;

        /** move point counts [left, right, up, down] */
        this.counts = [];

        this.set_target_node(target_node);

        /** Enable on creation */
        if (enable === true) {
            this.enable();
        }

    }

    /** 
    *   Set or reset target node
    *
    *   @param string/node target_node
    *   @param string      enable (optional)
    */
    set_target_node(target_node, enable=false) {

        /** check if we're resetting target_node */
        if (this.target_node !== null) {

            /** remove old listener */
           this.disable();
        }

        /** Support string id of node */
        if (target_node.nodeName === undefined) {
            target_node = document.getElementById(target_node);
        }

        this.target_node = target_node;

        if (enable === true) {
            this.enable();
        }
    }

    /** enable listener */
    enable() {
        this.enabled = true;
        this.target_node.addEventListener("touchstart", this.__touchstart.bind(this));
        this.target_node.addEventListener("touchmove", this.__touchmove.bind(this));
        this.target_node.addEventListener("touchend", this.__touchend.bind(this));
    }

    /** disable listener */
    disable() {
        this.enabled = false;
        this.target_node.removeEventListener("touchstart", this.__touchstart);
        this.target_node.removeEventListener("touchmove", this.__touchmove);
        this.target_node.removeEventListener("touchend", this.__touchend);
    }

    /** Touchstart */
    __touchstart(event) {
        event.stopPropagation();
        this.xdown = event.touches[0].clientX;
        this.ydown = event.touches[0].clientY;

        /** reset count of moves in each direction, [left, right, up, down] */
        this.counts = [0, 0, 0, 0];
    }

    /** Touchend */
    __touchend(event) {
        let max_moves = Math.max(...this.counts);
        if (max_moves > 500) { // set this threshold appropriately
            /** swipe happened */
            let index = this.counts.indexOf(max_moves);
            if (index == 0) {
                this.callback("left");
            } else if (index == 1) {
                this.callback("right");
            } else if (index == 2) {
                this.callback("up");
            } else {
                this.callback("down");
            }
        }
    }

    /** Touchmove */
    __touchmove(event) {

        event.stopPropagation();
        if (! this.xdown || ! this.ydown) {
            return;
        }

        let xup = event.touches[0].clientX;
        let yup = event.touches[0].clientY;

        let xdiff = this.xdown - xup;
        let ydiff = this.ydown - yup;

        /** Check x or y has greater distance */
        if (Math.abs(xdiff) > Math.abs(ydiff)) {
            if (xdiff > 0) {
                this.counts[0] += Math.abs(xdiff);
            } else {
                this.counts[1] += Math.abs(xdiff);
            }
        } else {
            if (ydiff > 0) {
                this.counts[2] += Math.abs(ydiff);
            } else {
                this.counts[3] += Math.abs(ydiff);
            }
        }
    }
}

其他回答

threshold, timeout swipe, swipeBlockElems添加。

document.addEventListener('touchstart', handleTouchStart, false);
document.addEventListener('touchmove', handleTouchMove, false);
document.addEventListener('touchend', handleTouchEnd, false);     

const SWIPE_BLOCK_ELEMS = [
  'swipBlock',
  'handle',
  'drag-ruble'
]

let xDown = null;
let yDown = null; 
let xDiff = null;
let yDiff = null;
let timeDown = null;
const  TIME_THRESHOLD = 200;
const  DIFF_THRESHOLD = 130;

function handleTouchEnd() {

let timeDiff = Date.now() - timeDown; 
if (Math.abs(xDiff) > Math.abs(yDiff)) { /*most significant*/
  if (Math.abs(xDiff) > DIFF_THRESHOLD && timeDiff < TIME_THRESHOLD) {
    if (xDiff > 0) {
      // console.log(xDiff, TIME_THRESHOLD, DIFF_THRESHOLD)
      SWIPE_LEFT(LEFT) /* left swipe */
    } else {
      // console.log(xDiff)
      SWIPE_RIGHT(RIGHT) /* right swipe */
    }
  } else {
    console.log('swipeX trashhold')
  }
} else {
  if (Math.abs(yDiff) > DIFF_THRESHOLD && timeDiff < TIME_THRESHOLD) {
    if (yDiff > 0) {
      /* up swipe */
    } else {
      /* down swipe */
    }
  } else {
    console.log('swipeY trashhold')
  }
 }
 /* reset values */
 xDown = null;
 yDown = null;
 timeDown = null; 
}
function containsClassName (evntarget , classArr) {
 for (var i = classArr.length - 1; i >= 0; i--) {
   if( evntarget.classList.contains(classArr[i]) ) {
      return true;
    }
  }
}
function handleTouchStart(evt) {
  let touchStartTarget = evt.target;
  if( containsClassName(touchStartTarget, SWIPE_BLOCK_ELEMS) ) {
    return;
  }
  timeDown = Date.now()
  xDown = evt.touches[0].clientX;
  yDown = evt.touches[0].clientY;
  xDiff = 0;
  yDiff = 0;

}

function handleTouchMove(evt) {
  if (!xDown || !yDown) {
    return;
  }

  var xUp = evt.touches[0].clientX;
  var yUp = evt.touches[0].clientY;


  xDiff = xDown - xUp;
  yDiff = yDown - yUp;
}

我之前使用的方法是,您必须检测mousedown事件,记录其x,y位置(任何相关的位置),然后检测mouseup事件,并减去两个值。

你可以监听touchstart和touchend事件,并根据事件数据计算方向和力(Codepen):

让start = null; 文档。addEventListener('touchstart', e => { const touch = e. changedtouchs[0]; Start = [touch.]clientX touch.clientY); }); 文档。addEventListener('touchend', e => { const touch = e. changedtouchs[0]; Const end = [touch.]clientX touch.clientY); document.body.innerText = " ${结束[0]-[0]开始},${结束[1]-[1]开始}'; }); 点击这里

或者你可以围绕同样的概念构建一个更符合人体工程学的API (Codepen):

const removeListener = addSwipeRightListener(document, (force, e) => {
  console.info('Swiped right with force: ' + force);
});
// removeListener()

// swipe.js const { addSwipeLeftListener, addSwipeRightListener, addSwipeUpListener, addSwipeDownListener, } = (function() { // <element, {listeners: [...], handleTouchstart, handleTouchend}> const elements = new WeakMap(); function readTouch(e) { const touch = e.changedTouches[0]; if (touch == undefined) { return null; } return [touch.clientX, touch.clientY]; } function addListener(element, cb) { let elementValues = elements.get(element); if (elementValues === undefined) { const listeners = new Set(); const handleTouchstart = e => { elementValues.start = readTouch(e); }; const handleTouchend = e => { const start = elementValues.start; if (start === null) { return; } const end = readTouch(e); for (const listener of listeners) { listener([end[0] - start[0], end[1] - start[1]], e); } }; element.addEventListener('touchstart', handleTouchstart); element.addEventListener('touchend', handleTouchend); elementValues = { start: null, listeners, handleTouchstart, handleTouchend, }; elements.set(element, elementValues); } elementValues.listeners.add(cb); return () => deleteListener(element, cb); } function deleteListener(element, cb) { const elementValues = elements.get(element); const listeners = elementValues.listeners; listeners.delete(cb); if (listeners.size === 0) { elements.delete(element); element.removeEventListener('touchstart', elementValues.handleTouchstart); element.removeEventListener('touchend', elementValues.handleTouchend); } } function addSwipeLeftListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (x < 0 && -x > Math.abs(y)) { cb(x, e); } }); } function addSwipeRightListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (x > 0 && x > Math.abs(y)) { cb(x, e); } }); } function addSwipeUpListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (y < 0 && -y > Math.abs(x)) { cb(x, e); } }); } function addSwipeDownListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (y > 0 && y > Math.abs(x)) { cb(x, e); } }); } return { addSwipeLeftListener, addSwipeRightListener, addSwipeUpListener, addSwipeDownListener, } })(); // app.js function print(direction, force) { document.querySelector('#direction').innerText = direction; document.querySelector('#data').innerText = force; } addSwipeLeftListener(document, (force, e) => { print('left', force); }); addSwipeRightListener(document, (force, e) => { print('right', force); }); addSwipeUpListener(document, (force, e) => { print('up', force); }); addSwipeDownListener(document, (force, e) => { print('down', force); }); <h1>Swipe <span id="direction"></span></h1> Force (px): <span id="data"></span>

函数检查水平方向和垂直方向,以确定哪个滑动更长,以防止执行两个指令,因为不可能进行完美的单向滑动。滑动总是在X和Y上有偏差。

let touchstartX = 0;
let touchendX = 0;
let touchstartY = 0;
let touchendY = 0;   

function checkDirection() {
    let difX = touchstartX - touchendX;
    let difY = touchstartY - touchendY;
if (Math.abs(difX) > Math.abs(difY)) {
    if (touchendX < touchstartX) {/*left*/}
    if (touchendX > touchstartX) {/*right*/}
} else {
    if (touchendY < touchstartY) {/*up*/}
    if (touchendY > touchstartY) {/*down*/}
}
};
document.addEventListener('touchstart', e => {
    e.preventDefault();
    touchstartX = e.changedTouches[0].screenX;
    touchstartY = e.changedTouches[0].screenY;
});

document.addEventListener('touchend', e => {
    e.preventDefault();
    touchendX = e.changedTouches[0].screenX;
    touchendY = e.changedTouches[0].screenY;
    checkDirection();
});

我重做了@ruben-martinez的答案,使用来自@givanse的惊人的解决方案,使用自定义反应钩子处理滑动事件。

import React, { useEffect, useRef, useState } from "react";

export default function useSwiper() {
  const [domRef, setDomRef] = useState<any>();

  const xDown: React.MutableRefObject<number | null> = useRef(null);
  const yDown: React.MutableRefObject<number | null> = useRef(null);

  useEffect(() => {
if (!domRef) return;

function getTouches(event: React.TouchEvent<HTMLDivElement>) {
  return event.touches;
}

function handleTouchStart(event: any) {
  const firstTouch = getTouches(event)[0];
  xDown.current = firstTouch.clientX;
  yDown.current = firstTouch.clientY;
}

function handleTouchMove(event: React.TouchEvent<HTMLDivElement>) {
  if (!xDown.current || !yDown.current) return;

  const firstTouch = getTouches(event)[0];
  const xUp = firstTouch.clientX;
  const yUp = firstTouch.clientY;

  const xDiff = xDown.current - xUp;
  const yDiff = yDown.current - yUp;

  if (Math.abs(xDiff) > Math.abs(yDiff)) {
    // handle horizontal swipes
    if (xDiff > 0) {
      // we swiped right
      console.log("right");
    } else {
      // we swiped left
      console.log("left");
    }
  } else {
    // handle vertical swipes
    if (yDiff > 0) {
      // we swiped down
      console.log("down");
    } else {
      // we swiped up
      console.log("up");
    }
  }
}

function handleTouchEnd(event: React.TouchEvent<HTMLDivElement>) {
  xDown.current = null;
  yDown.current = null;
}


  domRef.addEventListener("touchstart", handleTouchStart, false);
  domRef.addEventListener("touchmove", handleTouchMove, false);
  domRef.addEventListener("touchend", handleTouchEnd, false);

return () => {
    domRef.removeEventListener("touchstart", handleTouchStart, false);
    domRef.removeEventListener("touchmove", handleTouchMove, false);
    domRef.removeEventListener("touchend", handleTouchEnd, false);
};
  }, [domRef]);

  return (ref: any) => setDomRef(ref);
}

我在实现他的答案时遇到的主要挑战是不知道如何将swipe元素的ref绑定到自定义钩子中的ref。

基本上,所发生的是我们从自定义钩子返回一个函数。这个函数允许我们传入一个来自我们想要监听的滑动动作的元素的ref。自定义钩子接收到ref后,用元素的ref更新钩子状态,从而触发重新渲染,这样我们就有了实际的元素!

这种函数式的ref样式还允许我们对多个元素使用钩子。如下所示,我想使用它的项目列表,以启用滑动删除:)

import useSwiper from "./hooks/useSwipe";

const EntryCard = ({ entry, godMode, reload }: EntryProps) => {
const swiperRef = useSwiper();

const handleEntryClick =
(entry: Entry) => async (event: React.MouseEvent<HTMLDivElement>) => {
  if (!godMode) return;

  try {
    reload((state) => !state);
  } catch (err) {
    console.log("Error deleting entry: ", err);
  }
};

return (
  <div className="item" onClick={handleEntryClick(entry)} ref={swiperRef}>
    <div className="username">{entry.userName}</div>
    <div className="score">{entry.weekScore}</div>
  </div>
 );
};

PS:你可以把函数传递给钩子来接收滑动值。谢谢:)如果你喜欢,请投票:)