应该是CSS和JavaScript的结合体。要做的步骤应该是：
但是细节是什么？
这是来自 Javascript，权威指南 的示例（已更新此处）：
/**
* Drag.js: drag absolutely positioned HTML elements.
*
* This module defines a single drag() function that is designed to be called
* from an onmousedown event handler. Subsequent mousemove event will
* move the specified element. A mouseup event will terminate the drag.
* If the element is dragged off the screen, the window does not scroll.
* This implementation works with both the DOM Level 2 event model and the
* IE event model.
*
* Arguments:
*
* elementToDrag: the element that received the mousedown event or
* some containing element. It must be absolutely positioned. Its
* style.left and style.top values will be changed based on the user's
* drag.
*
* event: ethe Event object for the mousedown event.
*
* Example of how this can be used:
* <script src="Drag.js"></script> <!-- Include the Drag.js script -->
* <!-- Define the element to be dragged -->
* <div style="postion:absolute; left:100px; top:100px; width:250px;
* background-color: white; border: solid black;">
* <!-- Define the "handler" to drag it with. Note the onmousedown attribute. -->
* <div style="background-color: gray; border-bottom: dotted black;
* padding: 3px; font-family: sans-serif; font-weight: bold;"
* onmousedown="drag(this.parentNode, event);">
* Drag Me <!-- The content of the "titlebar" -->
* </div>
* <!-- Content of the draggable element -->
* <p>This is a test. Testing, testing, testing.<p>This is a test.<p>Test.
* </div>
*
* Author: David Flanagan; Javascript: The Definitive Guide (O'Reilly)
* Page: 422
**/
function drag(elementToDrag, event)
{
// The mouse position (in window coordinates)
// at which the drag begins
var startX = event.clientX, startY = event.clientY;
// The original position (in document coordinates) of the
// element that is going to be dragged. Since elementToDrag is
// absolutely positioned, we assume that its offsetParent is the
//document bodt.
var origX = elementToDrag.offsetLeft , origY = elementToDrag.offsetTop;
// Even though the coordinates are computed in different
// coordinate systems, we can still compute the difference between them
// and use it in the moveHandler() function. This works because
// the scrollbar positoin never changes during the drag.
var deltaX = startX - origX, deltaY = startY - origY;
// Register the event handlers that will respond to the mousemove events
// and the mouseup event that follow this mousedown event.
if (document.addEventListener) //DOM Level 2 event model
{
// Register capturing event handlers
document.addEventListener("mousemove", moveHandler, true);
document.addEventListener("mouseup", upHandler, true);
}
else if (document.attachEvent) //IE 5+ Event Model
{
//In the IE event model, we capture events by calling
//setCapture() on the element to capture them.
elementToDrag.setCapture();
elementToDrag.attachEvent("onmousemove", moveHandler);
elementToDrag.attachEvent("onmouseup", upHandler);
// Treat loss of mouse capture as a mouseup event.
elementToDrag.attachEvent("onclosecapture", upHandler);
}
else //IE 4 Event Model
{
// In IE 4, we can't use attachEvent() or setCapture(), so we set
// event handlers directly on the document object and hope that the
// mouse event we need will bubble up.
var oldmovehandler = document.onmousemove; //used by upHandler()
var olduphandler = document.onmouseup;
document.onmousemove = moveHandler;
document.onmouseup = upHandler;
}
// We've handled this event. Don't let anybody else see it.
if (event.stopPropagation) event.stopPropagation(); // DOM Level 2
else event.cancelBubble = true; // IE
// Now prevent any default action.
if (event.preventDefault) event.preventDefault(); // DOM Level 2
else event.returnValue = false; // IE
/**
* This is the handler that captures mousemove events when an element
* is being dragged. It is responsible for moving the element.
**/
function moveHandler(e)
{
if (!e) e = window.event; // IE Event Model
// Move the element to the current mouse position, adjusted as
// necessary by the offset of the initial mouse-click.
elementToDrag.style.left = (e.clientX - deltaX) + "px";
elementToDrag.style.top = (e.clientY - deltaY) + "px";
// And don't let anyone else see this event.
if (e.stopPropagation) e.stopPropagation(); // DOM Level 2
else e.cancelBubble = true; // IE
}
/**
* This is the handler that captures the final mouseup event that
* occurs at the end of a drag.
**/
function upHandler(e)
{
if (!e) e = window.event; //IE Event Model
// Unregister the capturing event handlers.
if (document.removeEventListener) // DOM event model
{
document.removeEventListener("mouseup", upHandler, true);
document.removeEventListener("mousemove", moveHandler, true);
}
else if (document.detachEvent) // IE 5+ Event Model
{
elementToDrag.detachEvent("onlosecapture", upHandler);
elementToDrag.detachEvent("onmouseup", upHandler);
elementToDrag.detachEvent("onmousemove", moveHandler);
elementToDrag.releaseCapture();
}
else //IE 4 Event Model
{
//Restore the original handlers, if any
document.onmouseup = olduphandler;
document.onmousemove = oldmovehandler;
}
// And don't let the event propagate any further.
if (e.stopPropagation) e.stopPropagation(); //DOM Level 2
else e.cancelBubble = true; //IE
}
}
function closeMe(elementToClose)
{
elementToClose.innerHTML = '';
elementToClose.style.display = 'none';
}
function minimizeMe(elementToMin, maxElement)
{
elementToMin.style.display = 'none';
}
如果您在 2017 年或之后阅读本文，您可能想看看 HTML5 拖放 API：
https://developer.mozilla.org/docs/Web/API/HTML_Drag_and_Drop_API
示例：
<!DOCTYPE HTML>
<html>
<head>
<script>
function allowDrop(ev) {
ev.preventDefault();
}
function drag(ev) {
ev.dataTransfer.setData("text", ev.target.id);
}
function drop(ev) {
ev.preventDefault();
var data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
}
</script>
<style>
.draggable {
border: 1px solid black;
width: 30px;
height: 20px;
float: left;
margin-right: 5px;
}
#target {
border: 1px solid black;
width: 150px;
height: 100px;
padding: 5px;
}
</style>
</head>
<body>
<h1>Drag and Drop</h1>
<h2>Target</h2>
<div id="target" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<h2>Draggable Elements</h2>
<div id="draggable1" class="draggable" draggable="true" ondragstart="drag(event)"></div>
<div id="draggable2" class="draggable" draggable="true" ondragstart="drag(event)"></div>
<div id="draggable3" class="draggable" draggable="true" ondragstart="drag(event)"></div>
</body>
</html>
标准的拖放 API 被广泛认为是“吸大毛驴球”。所以我不建议从头开始。但既然这是你的问题，那么有一组使某些东西可拖动的要求，以及一组正确设置拖放区域的要求： 拖动：
dom 节点必须将“draggable”属性设置为 true
e.dataTransfer.setDragImage可用于设置备用拖动图像（默认是被拖动的dom节点的透明图像。
注2：
e.dataTransfer.setData可以在
dragstart掉落：
在
dragovere.preventDefaultdrope.preventDefault<body>
<div id="dragme" draggable="true">Drag Me</div>
<div id="dropzone">Drop Here</div>
</body>
<script>
var dragme = document.getElementById('dragme')
var dropzone = document.getElementById('dropzone')
dragme.addEventListener('dragstart',function(e){
dropzone.innerHTML = "drop here"
})
dropzone.addEventListener('dragover',function(e){
e.preventDefault()
})
dropzone.addEventListener('drop',function(e){
e.preventDefault()
dropzone.innerHTML = "dropped"
})
</script>
但是，使用此 API 时存在很多问题，包括：
需要花费大量工作来区分放置区上的
dragmovedragmove即使鼠标没有移动，
dragmove即使你的鼠标没有移入或移出侦听 dom 节点，
dragleavedragenter
function allowDrop(ev) {
ev.preventDefault();
}
function drag(ev) {
ev.dataTransfer.setData("text", ev.target.id);
}
function drop(ev) {
ev.preventDefault();
var data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
}.mydiv {
float: left;
width: 100px;
height: 35px;
margin: 10px;
padding: 10px;
border: 1px solid black;
}<!DOCTYPE HTML>
<html>
<head>
</head>
<body>
<h2>Drag and Drop</h2>
<div id="div1" class="mydiv" ondrop="drop(event)" ondragover="allowDrop(event)">
<img src="https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-logo.png?v=9c558ec15d8a" draggable="true" ondragstart="drag(event)" id="drag1" width="88" height="31">
</div>
<div id="div2" class="mydiv" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<div id="div3" class="mydiv" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<div id="div4" class="mydiv" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="X-UA-Compatible" content="ie=edge" />
<title>Document</title>
<style>
body,
html {
width: 100%;
height: 100%;
padding: 0px;
margin: 0px;
}
#box {
width: 100px;
height: 100px;
margin: auto;
background-color: lightblue;
}
#box:active {
border: 1px solid black;
box-shadow: 2px 2px 5px 5px #bbb6b6;
}
</style>
</head>
<body>
<div id="box"></div>
</body>
<script>
var box = document.getElementById("box");
var diff = {};
var getBoxPos = function() {
return {
x: box.getBoundingClientRect().x,
y: box.getBoundingClientRect().y
};
};
var calcDiff = function(x, y) {
var boxPos = getBoxPos();
diff = {
x: x - boxPos.x,
y: y - boxPos.y
};
};
var handleMouseMove = function(event) {
var x = event.x;
var y = event.y;
x -= diff.x;
y -= diff.y;
console.log("X " + x + " Y " + y);
box.style.position = "absolute";
box.style.transform = "translate(" + x + "px ," + y + "px)";
};
box.addEventListener("mousedown", function(e) {
calcDiff(e.x, e.y);
box.addEventListener("mousemove", handleMouseMove, true);
});
box.addEventListener("mouseup", function(e) {
console.log("onmouseup");
box.removeEventListener("mousemove", handleMouseMove, true);
});
</script>
</html>
w3schools 有一个很好的例子：https://www.w3schools.com/howto/howto_js_draggable.asp
HTML：
<!-- Draggable DIV -->
<div id="mydiv">
<!-- Include a header DIV with the same name as the draggable DIV, followed by "header" -->
<div id="mydivheader">Click here to move</div>
<p>Move</p>
<p>this</p>
<p>DIV</p>
</div>
CSS：
#mydiv {
position: absolute;
z-index: 9;
background-color: #f1f1f1;
border: 1px solid #d3d3d3;
text-align: center;
}
#mydivheader {
padding: 10px;
cursor: move;
z-index: 10;
background-color: #2196F3;
color: #fff;
}
JS：
// Make the DIV element draggable:
dragElement(document.getElementById("mydiv"));
function dragElement(elmnt) {
var pos1 = 0, pos2 = 0, pos3 = 0, pos4 = 0;
if (document.getElementById(elmnt.id + "header")) {
// if present, the header is where you move the DIV from:
document.getElementById(elmnt.id + "header").onmousedown = dragMouseDown;
} else {
// otherwise, move the DIV from anywhere inside the DIV:
elmnt.onmousedown = dragMouseDown;
}
function dragMouseDown(e) {
e = e || window.event;
e.preventDefault();
// get the mouse cursor position at startup:
pos3 = e.clientX;
pos4 = e.clientY;
document.onmouseup = closeDragElement;
// call a function whenever the cursor moves:
document.onmousemove = elementDrag;
}
function elementDrag(e) {
e = e || window.event;
e.preventDefault();
// calculate the new cursor position:
pos1 = pos3 - e.clientX;
pos2 = pos4 - e.clientY;
pos3 = e.clientX;
pos4 = e.clientY;
// set the element's new position:
elmnt.style.top = (elmnt.offsetTop - pos2) + "px";
elmnt.style.left = (elmnt.offsetLeft - pos1) + "px";
}
function closeDragElement() {
// stop moving when mouse button is released:
document.onmouseup = null;
document.onmousemove = null;
}
}
您可以使用以下代码来完成此操作
$(function() {
$("#imageListId").sortable({
update: function(event, ui) {
getIdsOfImages();
} //end update
});
});
function getIdsOfImages() {
var values = [];
$('.listitemClass').each(function(index) {
values.push($(this).attr("id")
.replace("imageNo", ""));
});
$('#outputvalues').val(values);
}
/* text align for the body */
body {
text-align: center;
}
/* image dimension */
img {
height: 200px;
width: 350px;
}
/* imagelistId styling */
#imageListId {
margin: 0;
padding: 0;
list-style-type: none;
}
#imageListId div {
margin: 0 4px 4px 4px;
padding: 0.4em;
display: inline-block;
}
/* Output order styling */
#outputvalues {
margin: 0 2px 2px 2px;
padding: 0.4em;
padding-left: 1.5em;
width: 250px;
border: 2px solid dark-green;
background: gray;
}
.listitemClass {
border: 1px solid #006400;
width: 350px;
}
.height {
height: 10px;
}<link href="https://code.jquery.com/ui/1.10.4/themes/ui-lightness/jquery-ui.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="https://code.jquery.com/ui/1.10.4/jquery-ui.js"></script>
<!DOCTYPE html>
<html>
<head>
<title>
Drag Drop feature
</title>
</head>
<body>
<h1 style="color:green">GeeksforGeeks</h1>
<b>Drag and drop using jQuery UI Sortable</b>
<div class="height"></div><br>
<div id = "imageListId">
<div id="imageNo1" class = "listitemClass">
<img src="images/geeksimage1.png" alt="">
</div>
<div id="imageNo2" class = "listitemClass">
<img src="images/geeksimage2.png" alt="">
</div>
<div id="imageNo3" class = "listitemClass">
<img src="images/geeksimage3.png" alt="">
</div>
<div id="imageNo4" class = "listitemClass">
<img src="images/geeksimage4.png" alt="">
</div>
<div id="imageNo5" class = "listitemClass">
<img src="images/geeksimage5.png" alt="">
</div>
<div id="imageNo6" class = "listitemClass">
<img src="images/geeksimage6.png" alt="">
</div>
</div>
<div id="outputDiv">
<b>Output of ID's of images : </b>
<input id="outputvalues" type="text" value="" />
</div>
</body>
</html>