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

我重做了@givanse的解决方案,使其发挥React钩子的作用。输入是一些可选的事件监听器,输出是一个功能性的ref(需要是功能性的,以便当/如果ref改变时钩子可以重新运行)。

还添加了垂直/水平滑动阈值参数,这样小的运动不会意外触发事件监听器,但这些可以设置为0,以更接近地模拟原始答案。

提示:为了获得最佳性能,应该记住事件侦听器输入函数。

function useSwipeDetector({
    // Event listeners.
    onLeftSwipe,
    onRightSwipe,
    onUpSwipe,
    onDownSwipe,

    // Threshold to detect swipe.
    verticalSwipeThreshold = 50,
    horizontalSwipeThreshold = 30,
}) {
    const [domRef, setDomRef] = useState(null);
    const xDown = useRef(null);
    const yDown = useRef(null);

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

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

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

            const [firstTouch] = evt.touches;
            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)) {/*most significant*/
                if (xDiff > horizontalSwipeThreshold) {
                    if (onRightSwipe) onRightSwipe();
                } else if (xDiff < -horizontalSwipeThreshold) {
                    if (onLeftSwipe) onLeftSwipe();
                }
            } else {
                if (yDiff > verticalSwipeThreshold) {
                    if (onUpSwipe) onUpSwipe();
                } else if (yDiff < -verticalSwipeThreshold) {
                    if (onDownSwipe) onDownSwipe();
                }
            }
        };

        function handleTouchEnd() {
            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);
            domRef.removeEventListener("touchmove", handleTouchMove);
            domRef.removeEventListener("touchend", handleTouchEnd);
        };
    }, [domRef, onLeftSwipe, onRightSwipe, onUpSwipe, onDownSwipe, verticalSwipeThreshold, horizontalSwipeThreshold]);

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

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:)

我只想检测左右滑动,但只在触摸事件结束时触发动作,所以我稍微修改了@givanse的答案来实现这一点。

为什么要这么做?例如,在滑动时,用户注意到他最终不想滑动,他可以将手指移动到原来的位置(一个非常流行的“约会”手机应用程序可以做到这一点;)),然后“向右滑动”事件被取消。

因此,为了避免因为水平上有3px的差异而导致“向右滑动”事件,我添加了一个阈值,在该阈值下事件将被丢弃:为了有一个“向右滑动”事件,用户必须至少滑动浏览器宽度的1/3(当然,您可以修改这个)。

所有这些小细节都增强了用户体验。

请注意,目前,如果两个手指中的一个在缩放过程中做了一个大的水平移动,那么“触摸缩放”可能会被检测为滑动。

这是(Vanilla JS)代码:

var xDown = null, yDown = null, xUp = null, yUp = null;
document.addEventListener('touchstart', touchstart, false);        
document.addEventListener('touchmove', touchmove, false);
document.addEventListener('touchend', touchend, false);
function touchstart(evt) { const firstTouch = (evt.touches || evt.originalEvent.touches)[0]; xDown = firstTouch.clientX; yDown = firstTouch.clientY; }
function touchmove(evt) { if (!xDown || !yDown ) return; xUp = evt.touches[0].clientX; yUp = evt.touches[0].clientY; }
function touchend(evt) { 
    var xDiff = xUp - xDown, yDiff = yUp - yDown;
    if ((Math.abs(xDiff) > Math.abs(yDiff)) && (Math.abs(xDiff) > 0.33 * document.body.clientWidth)) { 
        if (xDiff < 0) 
            document.getElementById('leftnav').click();
        else
            document.getElementById('rightnav').click();
    } 
    xDown = null, yDown = null;
}

我将这里的一些答案合并到一个脚本中,该脚本使用CustomEvent在DOM中触发滑动事件。添加0.7k的swiped-events.min.js脚本到你的页面,并监听滑动事件:

刷卡

document.addEventListener('swiped', function(e) {
    console.log(e.target); // the element that was swiped
    console.log(e.detail.dir); // swiped direction
});

swiped-left

document.addEventListener('swiped-left', function(e) {
    console.log(e.target); // the element that was swiped
});

swiped-right

document.addEventListener('swiped-right', function(e) {
    console.log(e.target); // the element that was swiped
});

swiped-up

document.addEventListener('swiped-up', function(e) {
    console.log(e.target); // the element that was swiped
});

swiped-down

document.addEventListener('swiped-down', function(e) {
    console.log(e.target); // the element that was swiped
});

你也可以直接附加到一个元素:

document.getElementById('myBox').addEventListener('swiped-down', function(e) {
    console.log(e.target); // the element that was swiped
});

可选配置

您可以指定以下属性来调整页面中的滑动交互功能(这些是可选的)。

<div data-swipe-threshold="10"
     data-swipe-timeout="1000"
     data-swipe-ignore="false">
      Swiper, get swiping!
</div>

要在应用程序范围内设置默认值,请在最顶部的元素上设置配置属性:

<body data-swipe-threshold="100" data-swipe-timeout="250">
    <div>Swipe me</div>
    <div>or me</div>
</body>

源代码可在Github