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
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
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'
});
})
我重做了@ruben-martinez的答案,使用来自@givanse的惊人的解决方案,使用自定义反应钩子处理滑动事件。
import React, { useEffect, useRef, useState } from "react";
export default function useSwiper() {
const [domRef, setDomRef] = useState<any>();
const xDown: React.MutableRefObject<number | null> = useRef(null);
const yDown: React.MutableRefObject<number | null> = useRef(null);
useEffect(() => {
if (!domRef) return;
function getTouches(event: React.TouchEvent<HTMLDivElement>) {
return event.touches;
}
function handleTouchStart(event: any) {
const firstTouch = getTouches(event)[0];
xDown.current = firstTouch.clientX;
yDown.current = firstTouch.clientY;
}
function handleTouchMove(event: React.TouchEvent<HTMLDivElement>) {
if (!xDown.current || !yDown.current) return;
const firstTouch = getTouches(event)[0];
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)) {
// handle horizontal swipes
if (xDiff > 0) {
// we swiped right
console.log("right");
} else {
// we swiped left
console.log("left");
}
} else {
// handle vertical swipes
if (yDiff > 0) {
// we swiped down
console.log("down");
} else {
// we swiped up
console.log("up");
}
}
}
function handleTouchEnd(event: React.TouchEvent<HTMLDivElement>) {
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, false);
domRef.removeEventListener("touchmove", handleTouchMove, false);
domRef.removeEventListener("touchend", handleTouchEnd, false);
};
}, [domRef]);
return (ref: any) => setDomRef(ref);
}
我在实现他的答案时遇到的主要挑战是不知道如何将swipe元素的ref绑定到自定义钩子中的ref。
基本上,所发生的是我们从自定义钩子返回一个函数。这个函数允许我们传入一个来自我们想要监听的滑动动作的元素的ref。自定义钩子接收到ref后,用元素的ref更新钩子状态,从而触发重新渲染,这样我们就有了实际的元素!
这种函数式的ref样式还允许我们对多个元素使用钩子。如下所示,我想使用它的项目列表,以启用滑动删除:)
import useSwiper from "./hooks/useSwipe";
const EntryCard = ({ entry, godMode, reload }: EntryProps) => {
const swiperRef = useSwiper();
const handleEntryClick =
(entry: Entry) => async (event: React.MouseEvent<HTMLDivElement>) => {
if (!godMode) return;
try {
reload((state) => !state);
} catch (err) {
console.log("Error deleting entry: ", err);
}
};
return (
<div className="item" onClick={handleEntryClick(entry)} ref={swiperRef}>
<div className="username">{entry.userName}</div>
<div className="score">{entry.weekScore}</div>
</div>
);
};
PS:你可以把函数传递给钩子来接收滑动值。谢谢:)如果你喜欢,请投票:)
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。
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。
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/