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。
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
在这里的建议之上,我将跟踪手指号码,因为如果你同时用两个手指触摸,它将获得X位置,而不会导致一个奇怪的行为,而且,你可能想要设置一个“距离”最小值,这样用户在通过你的网站或应用程序触摸时就不会错误地触发滑动。
//Swipe
let touchstartX = 0
let touchendX = 0
let fingerCount = 0
const checkDirection = () => {
const distance = 50 //Minimum distance for the swipe to work
//left
if (touchendX < touchstartX && (touchstartX - touchendX) > distance ){
//Do something cool
}
//right
if (touchendX > touchstartX && (touchendX - touchstartX) > distance){
//Do something cooler
}
document.addEventListener('touchstart', e => {
fingerCount = e.touches.length
touchstartX = e.changedTouches[0].clientX
})
document.addEventListener('touchend', e => {
touchendX = e.changedTouches[0].clientX
if(fingerCount === 1){
checkDirection()
}
})
其他回答
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'
});
})
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/
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();
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] }
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!') })
});