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JS代码示例:

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

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 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 ) ) {/*most significant*/
        if ( xDiff > 0 ) {
            /* right swipe */ 
        } else {
            /* left swipe */
        }                       
    } else {
        if ( yDiff > 0 ) {
            /* down swipe */ 
        } else { 
            /* up swipe */
        }                                                                 
    }
    /* reset values */
    xDown = null;
    yDown = null;                                             
};

Android测试。

其他回答

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!') })
});

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);
};

使用两个:

jQuery移动控件:在大多数情况下都可以工作,特别是当你在开发使用其他jQuery插件的应用程序时,最好使用jQuery移动控件。请访问:https://www.w3schools.com/jquerymobile/jquerymobile_events_touch.asp

锤子时间!一个最好的,轻量级和快速的基于javascript的库。请访问:https://hammerjs.github.io/

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'
  });
})