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

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>

其他回答

一些mod的顶部回答(不能评论…)来处理短滑动

document.addEventListener('touchstart', handleTouchStart, false);        
document.addEventListener('touchmove', handleTouchMove, false);
var xDown = null;                                                        
var yDown = null;                                                        
function handleTouchStart(evt) {                                         
    xDown = evt.touches[0].clientX;                                      
    yDown = evt.touches[0].clientY;                                      
};                                                
function handleTouchMove(evt) {
    if ( ! xDown || ! yDown ) {
        return;
    }

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

    var xDiff = xDown - xUp;
    var yDiff = yDown - yUp;
    if(Math.abs( xDiff )+Math.abs( yDiff )>150){ //to deal with to short swipes

    if ( Math.abs( xDiff ) > Math.abs( yDiff ) ) {/*most significant*/
        if ( xDiff > 0 ) {/* left swipe */ 
            alert('left!');
        } else {/* right swipe */
            alert('right!');
        }                       
    } else {
        if ( yDiff > 0 ) {/* up swipe */
            alert('Up!'); 
        } else { /* down swipe */
            alert('Down!');
        }                                                                 
    }
    /* reset values */
    xDown = null;
    yDown = null;
    }
};

我也合并了一些答案,主要是第一个和第二个与类,下面是我的版本:

export default class Swipe {
    constructor(options) {
        this.xDown = null;
        this.yDown = null;

        this.options = options;

        this.handleTouchStart = this.handleTouchStart.bind(this);
        this.handleTouchMove = this.handleTouchMove.bind(this);

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

    }

    onLeft() {
        this.options.onLeft();
    }

    onRight() {
        this.options.onRight();
    }

    onUp() {
        this.options.onUp();
    }

    onDown() {
        this.options.onDown();
    }

    static getTouches(evt) {
        return evt.touches      // browser API

    }

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

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

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

        let xDiff = this.xDown - xUp;
        let yDiff = this.yDown - yUp;


        if ( Math.abs( xDiff ) > Math.abs( yDiff ) ) {/*most significant*/
            if ( xDiff > 0 && this.options.onLeft) {
                /* left swipe */
                this.onLeft();
            } else if (this.options.onRight) {
                /* right swipe */
                this.onRight();
            }
        } else {
            if ( yDiff > 0 && this.options.onUp) {
                /* up swipe */
                this.onUp();
            } else if (this.options.onDown){
                /* down swipe */
                this.onDown();
            }
        }

        /* reset values */
        this.xDown = null;
        this.yDown = null;
    }
}

之后可以这样使用:

let swiper = new Swipe({
                    onLeft() {
                        console.log('You swiped left.');
                    }
});

当你只想调用“onLeft”方法时,它有助于避免控制台错误。

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。

再加上这个答案。这个增加了对鼠标事件的支持,用于桌面测试:

<!--scripts-->
class SwipeEventDispatcher {
    constructor(element, options = {}) {
        this.evtMap = {
            SWIPE_LEFT: [],
            SWIPE_UP: [],
            SWIPE_DOWN: [],
            SWIPE_RIGHT: []
        };

        this.xDown = null;
        this.yDown = null;
        this.element = element;
        this.isMouseDown = false;
        this.listenForMouseEvents = true;
        this.options = Object.assign({ triggerPercent: 0.3 }, options);

        element.addEventListener('touchstart', evt => this.handleTouchStart(evt), false);
        element.addEventListener('touchend', evt => this.handleTouchEnd(evt), false);
        element.addEventListener('mousedown', evt => this.handleMouseDown(evt), false);
        element.addEventListener('mouseup', evt => this.handleMouseUp(evt), false);
    }

    on(evt, cb) {
        this.evtMap[evt].push(cb);
    }

    off(evt, lcb) {
        this.evtMap[evt] = this.evtMap[evt].filter(cb => cb !== lcb);
    }

    trigger(evt, data) {
        this.evtMap[evt].map(handler => handler(data));
    }

    handleTouchStart(evt) {
        this.xDown = evt.touches[0].clientX;
        this.yDown = evt.touches[0].clientY;
    }

    handleMouseDown(evt) {
        if (this.listenForMouseEvents==false) return;
        this.xDown = evt.clientX;
        this.yDown = evt.clientY;
        this.isMouseDown = true;
    }

    handleMouseUp(evt) {
        if (this.isMouseDown == false) return;
        const deltaX = evt.clientX - this.xDown;
        const deltaY = evt.clientY - this.yDown;
        const distMoved = Math.abs(Math.abs(deltaX) > Math.abs(deltaY) ? deltaX : deltaY);
        const activePct = distMoved / this.element.offsetWidth;

        if (activePct > this.options.triggerPercent) {
            if (Math.abs(deltaX) > Math.abs(deltaY)) {
                deltaX < 0 ? this.trigger('SWIPE_LEFT') : this.trigger('SWIPE_RIGHT');
            } else {
                deltaY > 0 ? this.trigger('SWIPE_UP') : this.trigger('SWIPE_DOWN');
            }
        }
    }

    handleTouchEnd(evt) {
        const deltaX = evt.changedTouches[0].clientX - this.xDown;
        const deltaY = evt.changedTouches[0].clientY - this.yDown;
        const distMoved = Math.abs(Math.abs(deltaX) > Math.abs(deltaY) ? deltaX : deltaY);
        const activePct = distMoved / this.element.offsetWidth;

        if (activePct > this.options.triggerPercent) {
            if (Math.abs(deltaX) > Math.abs(deltaY)) {
                deltaX < 0 ? this.trigger('SWIPE_LEFT') : this.trigger('SWIPE_RIGHT');
            } else {
                deltaY > 0 ? this.trigger('SWIPE_UP') : this.trigger('SWIPE_DOWN');
            }
        }
    }
}

// add a listener on load
window.addEventListener("load", function(event) {
    const dispatcher = new SwipeEventDispatcher(document.body);
    dispatcher.on('SWIPE_RIGHT', () => { console.log('I swiped right!') })
    dispatcher.on('SWIPE_LEFT', () => { console.log('I swiped left!') })
});

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();
});