我必须为旋转木马编写一个简单的脚本，以检测向左或向右的滑动。

我使用指针事件代替触摸事件。

我希望这对个人有用，我欢迎任何改进我的代码的见解;我觉得很不好意思加入这个线程与显著优秀的JS开发人员。

function getSwipeX({elementId}) {

  this.e               = document.getElementsByClassName(elementId)[0];
  this.initialPosition = 0;
  this.lastPosition    = 0;
  this.threshold       = 200;
  this.diffInPosition  = null;
  this.diffVsThreshold = null;
  this.gestureState    = 0;

  this.getTouchStart = (event) => {
    event.preventDefault();
    if (window.PointerEvent) {
      this.e.setPointerCapture(event.pointerId);
    }
    return this.initalTouchPos = this.getGesturePoint(event);
  }

  this.getTouchMove  = (event) => {
    event.preventDefault();
    return this.lastPosition = this.getGesturePoint(event);
  }

  this.getTouchEnd   = (event) => {
    event.preventDefault();
    if (window.PointerEvent) {
      this.e.releasePointerCapture(event.pointerId);
    }
    this.doSomething();
    this.initialPosition = 0;
  }

  this.getGesturePoint = (event) => {
    this.point = event.pageX
    return this.point;
  }

  this.whatGestureDirection = (event) => {
    this.diffInPosition  = this.initalTouchPos - this.lastPosition;
    this.diffVsThreshold = Math.abs(this.diffInPosition) > this.threshold;
    (Math.sign(this.diffInPosition) > 0) ? this.gestureState = 'L' : (Math.sign(this.diffInPosition) < 0) ? this.gestureState = 'R' : this.gestureState = 'N';
    
    return [this.diffInPosition, this.diffVsThreshold, this.gestureState];
  }

  this.doSomething = (event) => {
    let [gestureDelta,gestureThreshold,gestureDirection] = this.whatGestureDirection();

    // USE THIS TO DEBUG
    console.log(gestureDelta,gestureThreshold,gestureDirection);

    if (gestureThreshold) {
      (gestureDirection == 'L') ? // LEFT ACTION : // RIGHT ACTION
    }
  }

  if (window.PointerEvent) {
    this.e.addEventListener('pointerdown', this.getTouchStart, true);
    this.e.addEventListener('pointermove', this.getTouchMove, true);
    this.e.addEventListener('pointerup', this.getTouchEnd, true);
    this.e.addEventListener('pointercancel', this.getTouchEnd, true);
  }
}

可以使用new调用该函数。

window.addEventListener('load', () => {
  let test = new getSwipeX({
    elementId: 'your_div_here'
  });
})

如果有人试图在Android上使用jQuery Mobile，并且有JQM滑动检测的问题

(我在Xperia Z1, Galaxy S3, Nexus 4和一些Wiko手机上也有一些)这可能很有用:

 //Fix swipe gesture on android
    if(android){ //Your own device detection here
        $.event.special.swipe.verticalDistanceThreshold = 500
        $.event.special.swipe.horizontalDistanceThreshold = 10
    }

在android上的滑动不会被检测到，除非它是一个非常长、精确和快速的滑动。

这两条线可以正常工作

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。

touchStart和touchEnd的句柄:

var handleSwipe = function(elem,callbackOnRight, callbackOnLeft, callbackOnDown, 
      callbackOnUp) => {

        elem.ontouchstart = handleTouchStart;
        elem.ontouchend = handleTouchEnd;

        var xDown = null;
        var yDown = null;

        function getTouches(evt) {
            return evt.touches ||             // browser API
                evt.originalEvent.touches; // jQuery
        }

        function handleTouchStart(evt) {
            const firstTouch = getTouches(evt)[0];
            xDown = firstTouch.clientX;
            yDown = firstTouch.clientY;
        };

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

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

            var xDiff = xDown - xUp;
            var yDiff = yDown - yUp;
            var minDif = 30;

            console.log(`xDiff:${xDiff}, yDiff:${yDiff}`);

            if (Math.abs(xDiff) > Math.abs(yDiff)) {
                if (xDiff > minDif) {
                    if (callbackOnLeft)
                        callbackOnLeft();
                } else if (xDiff < -1 * minDif){
                    if (callbackOnRight)
                        callbackOnRight();
                }
            } else {
                if (yDiff > minDif) {
                    if (callbackOnDown)
                        callbackOnDown();
                } else if (yDiff < -1* minDif){
                    if (callbackOnUp)
                        callbackOnUp();
                }
            }
            
            xDown = null;
            yDown = null;
        };
    }

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);
            }
        }
    }
}

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:)