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

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;
}

其他回答

一个如何使用偏移量的例子。

// at least 100 px are a swipe // you can use the value relative to screen size: window.innerWidth * .1 const offset = 100; let xDown, yDown window.addEventListener('touchstart', e => { const firstTouch = getTouch(e); xDown = firstTouch.clientX; yDown = firstTouch.clientY; }); window.addEventListener('touchend', e => { if (!xDown || !yDown) { return; } const { clientX: xUp, clientY: yUp } = getTouch(e); const xDiff = xDown - xUp; const yDiff = yDown - yUp; const xDiffAbs = Math.abs(xDown - xUp); const yDiffAbs = Math.abs(yDown - yUp); // at least <offset> are a swipe if (Math.max(xDiffAbs, yDiffAbs) < offset ) { return; } if (xDiffAbs > yDiffAbs) { if ( xDiff > 0 ) { console.log('left'); } else { console.log('right'); } } else { if ( yDiff > 0 ) { console.log('up'); } else { console.log('down'); } } }); function getTouch (e) { return e.changedTouches[0] }

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!') })
});

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。

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();
});