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
jQuery Mobile还包括滑动支持:http://api.jquerymobile.com/swipe/
例子
$("#divId").on("swipe", function(event) {
alert("It's a swipe!");
});
其他回答
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/
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!') })
});
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()
}
})
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] }
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。