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

简单的水平滑动JS示例:

let touchstartX = 0
let touchendX = 0
    
function checkDirection() {
  if (touchendX < touchstartX) alert('swiped left!')
  if (touchendX > touchstartX) alert('swiped right!')
}

document.addEventListener('touchstart', e => {
  touchstartX = e.changedTouches[0].screenX
})

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

垂直滑动也可以使用相同的逻辑。

其他回答

我重新包装了TouchWipe作为一个简短的jquery插件:detectSwipe

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();
});

根据@givanse的回答,以下是你可以用类来做的:

class Swipe {
    constructor(element) {
        this.xDown = null;
        this.yDown = null;
        this.element = typeof(element) === 'string' ? document.querySelector(element) : element;

        this.element.addEventListener('touchstart', function(evt) {
            this.xDown = evt.touches[0].clientX;
            this.yDown = evt.touches[0].clientY;
        }.bind(this), false);

    }

    onLeft(callback) {
        this.onLeft = callback;

        return this;
    }

    onRight(callback) {
        this.onRight = callback;

        return this;
    }

    onUp(callback) {
        this.onUp = callback;

        return this;
    }

    onDown(callback) {
        this.onDown = callback;

        return this;
    }

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

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

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

        if ( Math.abs( this.xDiff ) > Math.abs( this.yDiff ) ) { // Most significant.
            if ( this.xDiff > 0 ) {
                this.onLeft();
            } else {
                this.onRight();
            }
        } else {
            if ( this.yDiff > 0 ) {
                this.onUp();
            } else {
                this.onDown();
            }
        }

        // Reset values.
        this.xDown = null;
        this.yDown = null;
    }

    run() {
        this.element.addEventListener('touchmove', function(evt) {
            this.handleTouchMove(evt).bind(this);
        }.bind(this), false);
    }
}

你可以这样使用它:

// Use class to get element by string.
var swiper = new Swipe('#my-element');
swiper.onLeft(function() { alert('You swiped left.') });
swiper.run();

// Get the element yourself.
var swiper = new Swipe(document.getElementById('#my-element'));
swiper.onLeft(function() { alert('You swiped left.') });
swiper.run();

// One-liner.
(new Swipe('#my-element')).onLeft(function() { alert('You swiped left.') }).run();

如果你只需要滑动,你最好只使用你需要的部分。 这应该适用于任何触摸设备。

这是经过gzip压缩,缩小,babel等大约450字节。

我根据其他答案编写了下面的类,它使用移动百分比而不是像素,以及一个事件分派器模式来挂钩/取消挂钩。

像这样使用它:

const dispatcher = new SwipeEventDispatcher(myElement);
dispatcher.on('SWIPE_RIGHT', () => { console.log('I swiped right!') })

export 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.options = Object.assign({ triggerPercent: 0.3 }, options); element.addEventListener('touchstart', evt => this.handleTouchStart(evt), false); element.addEventListener('touchend', evt => this.handleTouchEnd(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; } 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'); } } } } export default SwipeEventDispatcher;

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;
    }
};