我使用jQuery。点击来处理Raphael图形上的鼠标点击事件，同时，我需要处理鼠标拖动事件，鼠标拖动在Raphael中由鼠标下拉，鼠标上拉和鼠标移动组成。
很难区分点击和拖动，因为点击也包含鼠标下拉和鼠标上拉，我怎么能区分鼠标“点击”和鼠标“拖动”然后在Javascript?
当前回答
基于这个答案，我在React组件中这样做:
export default React.memo(() => {
const containerRef = React.useRef(null);
React.useEffect(() => {
document.addEventListener('mousedown', handleMouseMove);
return () => document.removeEventListener('mousedown', handleMouseMove);
}, []);
const handleMouseMove = React.useCallback(() => {
const drag = (e) => {
console.log('mouse is moving');
};
const lift = (e) => {
console.log('mouse move ended');
window.removeEventListener('mousemove', drag);
window.removeEventListener('mouseup', this);
};
window.addEventListener('mousemove', drag);
window.addEventListener('mouseup', lift);
}, []);
return (
<div style={{ width: '100vw', height: '100vh' }} ref={containerRef} />
);
})
其他回答
如果你已经在使用jQuery:
var $body = $('body');
$body.on('mousedown', function (evt) {
$body.on('mouseup mousemove', function handler(evt) {
if (evt.type === 'mouseup') {
// click
} else {
// drag
}
$body.off('mouseup mousemove', handler);
});
});
如果只是为了过滤掉拖动的情况，这样做:
var moved = false;
$(selector)
.mousedown(function() {moved = false;})
.mousemove(function() {moved = true;})
.mouseup(function(event) {
if (!moved) {
// clicked without moving mouse
}
});
对于OSM地图上的公共操作(单击时放置标记)，问题是:1)如何确定鼠标向下的持续时间->向上(您无法想象为每次单击创建一个新的标记)2)鼠标向下移动期间->向上(即用户正在拖动地图)。
const map = document.getElementById('map');
map.addEventListener("mousedown", position);
map.addEventListener("mouseup", calculate);
let posX, posY, endX, endY, t1, t2, action;
function position(e) {
posX = e.clientX;
posY = e.clientY;
t1 = Date.now();
}
function calculate(e) {
endX = e.clientX;
endY = e.clientY;
t2 = (Date.now()-t1)/1000;
action = 'inactive';
if( t2 > 0.5 && t2 < 1.5) { // Fixing duration of mouse down->up
if( Math.abs( posX-endX ) < 5 && Math.abs( posY-endY ) < 5 ) { // 5px error on mouse pos while clicking
action = 'active';
// --------> Do something
}
}
console.log('Down = '+posX + ', ' + posY+'\nUp = '+endX + ', ' + endY+ '\nAction = '+ action);
}
基于这个答案，我在React组件中这样做:
export default React.memo(() => {
const containerRef = React.useRef(null);
React.useEffect(() => {
document.addEventListener('mousedown', handleMouseMove);
return () => document.removeEventListener('mousedown', handleMouseMove);
}, []);
const handleMouseMove = React.useCallback(() => {
const drag = (e) => {
console.log('mouse is moving');
};
const lift = (e) => {
console.log('mouse move ended');
window.removeEventListener('mousemove', drag);
window.removeEventListener('mouseup', this);
};
window.addEventListener('mousemove', drag);
window.addEventListener('mouseup', lift);
}, []);
return (
<div style={{ width: '100vw', height: '100vh' }} ref={containerRef} />
);
})
有同样的问题，最近在一个树列表中，用户可以点击项目或拖动它，使这个小指针类，并把它放在我的utils.js
function Pointer(threshold = 10) {
let x = 0;
let y = 0;
return {
start(e) {
x = e.clientX;
y = e.clientY;
},
isClick(e) {
const deltaX = Math.abs(e.clientX - x);
const deltaY = Math.abs(e.clientY - y);
return deltaX < threshold && deltaY < threshold;
}
}
}
下面你可以看到它的工作原理:
function Pointer(threshold = 10) { let x = 0; let y = 0; return { start(e) { x = e.clientX; y = e.clientY; }, isClick(e) { const deltaX = Math.abs(e.clientX - x); const deltaY = Math.abs(e.clientY - y); return deltaX < threshold && deltaY < threshold; } } } const pointer = new Pointer(); window.addEventListener('mousedown', (e) => pointer.start(e)) //window.addEventListener('mousemove', (e) => pointer.last(e)) window.addEventListener('mouseup', (e) => { const operation = pointer.isClick(e) ? "Click" : "Drag" console.log(operation) })
