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

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) })

其他回答

所有这些解决方案要么在微小的鼠标移动上失效,要么过于复杂。

下面是一个使用两个事件侦听器的简单适应性解决方案。Delta是您必须在上下事件之间水平或垂直移动的距离(以像素为单位),以便代码将其归类为拖拽而不是单击。这是因为有时你会在抬起鼠标或手指之前移动几个像素点。

const delta = 6;
let startX;
let startY;

element.addEventListener('mousedown', function (event) {
  startX = event.pageX;
  startY = event.pageY;
});

element.addEventListener('mouseup', function (event) {
  const diffX = Math.abs(event.pageX - startX);
  const diffY = Math.abs(event.pageY - startY);

  if (diffX < delta && diffY < delta) {
    // Click!
  }
});

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");
});

我认为区别在于,在拖拽中,mousedown和mouseup之间有一个鼠标移动,但在点击中没有。

你可以这样做:

const element = document.createElement('div') element.innerHTML = 'test' document.body.appendChild(element) let moved let downListener = () => { moved = false } element.addEventListener('mousedown', downListener) let moveListener = () => { moved = true } element.addEventListener('mousemove', moveListener) let upListener = () => { if (moved) { console.log('moved') } else { console.log('not moved') } } element.addEventListener('mouseup', upListener) // release memory element.removeEventListener('mousedown', downListener) element.removeEventListener('mousemove', moveListener) element.removeEventListener('mouseup', upListener)

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>

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);
}