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
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
}
});
其他回答
清洁ES2015
Let drag = false; 文档。addEventListener('mousedown'， () => drag = false); 文档。addEventListener('mousemove'， () => drag = true); 文档。addEventListener('mouseup'， () => console.log(拖动?'拖动':'点击'));
正如其他人评论的那样，没有遇到任何bug。
另一个基于类的香草JS使用距离阈值的解决方案
private initDetectDrag(element) {
let clickOrigin = { x: 0, y: 0 };
const dragDistanceThreshhold = 20;
element.addEventListener('mousedown', (event) => {
this.isDragged = false
clickOrigin = { x: event.clientX, y: event.clientY };
});
element.addEventListener('mousemove', (event) => {
if (Math.sqrt(Math.pow(clickOrigin.y - event.clientY, 2) + Math.pow(clickOrigin.x - event.clientX, 2)) > dragDistanceThreshhold) {
this.isDragged = true
}
});
}
在类内部添加(SOMESLIDER_ELEMENT也可以是document为global):
private isDragged: boolean;
constructor() {
this.initDetectDrag(SOMESLIDER_ELEMENT);
this.doSomeSlideStuff(SOMESLIDER_ELEMENT);
element.addEventListener('click', (event) => {
if (!this.sliderIsDragged) {
console.log('was clicked');
} else {
console.log('was dragged, ignore click or handle this');
}
}, false);
}
使用jQuery和5像素x/y暂停来检测拖动:
var dragging = false;
$("body").on("mousedown", function(e) {
var x = e.screenX;
var y = e.screenY;
dragging = false;
$("body").on("mousemove", function(e) {
if (Math.abs(x - e.screenX) > 5 || Math.abs(y - e.screenY) > 5) {
dragging = true;
}
});
});
$("body").on("mouseup", function(e) {
$("body").off("mousemove");
console.log(dragging ? "drag" : "click");
});
你可以这样做:
var div = document.getElementById("div"); div.addEventListener("mousedown", function() { window.addEventListener("mousemove", drag); window.addEventListener("mouseup", lift); var didDrag = false; function drag() { //when the person drags their mouse while holding the mouse button down didDrag = true; div.innerHTML = "drag" } function lift() { //when the person lifts mouse if (!didDrag) { //if the person didn't drag div.innerHTML = "click"; } else div.innerHTML = "drag"; //delete event listeners so that it doesn't keep saying drag window.removeEventListener("mousemove", drag) window.removeEventListener("mouseup", this) } }) body { outline: none; box-sizing: border-box; margin: 0; padding: 0; font-family: Arial, Helvetica, sans-serif; overflow: hidden; } #div { /* calculating -5px for each side of border in case border-box doesn't work */ width: calc(100vw - 10px); height: calc(100vh - 10px); border: 5px solid orange; background-color: yellow; font-weight: 700; display: grid; place-items: center; user-select: none; cursor: pointer; padding: 0; margin: 0; } <html> <body> <div id="div">Click me or drag me.</div> </body> </html>
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} />
);
})
