我正在尝试使一个 div 具有可拖动性，但不使用 jQuery UI。
然而，我被下面的代码困住了。我知道应该使用鼠标相对于容器 div 的位置（在其中 div 将被拖动），并且我应该设置 div 的偏移量相对于这些值。
我只是想不出如何做到这一点。有什么提示吗？
这是当然不起作用的代码：
var X, Y;
$(this).mousedown(function() {
$(this).offset({
left: X,
top: Y
});
});
$("#containerDiv").mousemove(function(event) {
X = event.pageX;
Y = event.pageY;
});
这是一个非常简单的例子，可能会让你入门:
$(document).ready(function() {
var $dragging = null;
$(document.body).on("mousemove", function(e) {
if ($dragging) {
$dragging.offset({
top: e.pageY,
left: e.pageX
});
}
});
$(document.body).on("mousedown", "div", function (e) {
$dragging = $(e.target);
});
$(document.body).on("mouseup", function (e) {
$dragging = null;
});
});
我理解应该使用鼠标位置相对于容器 div（在其中拖动 div）并设置 div 的偏移量相对于那些值。
我不太确定。 在拖放中，似乎您总是希望使用元素相对于文档的偏移量。
如果您的意思是要将拖动限制在特定区域内，则这是一个更复杂的问题（但仍然可行）。
这是另一个更新后的代码:
$(document).ready(function() {
var $dragging = null;
$('body').on("mousedown", "div", function(e) {
$(this).attr('unselectable', 'on').addClass('draggable');
var el_w = $('.draggable').outerWidth(),
el_h = $('.draggable').outerHeight();
$('body').on("mousemove", function(e) {
if ($dragging) {
$dragging.offset({
top: e.pageY - el_h / 2,
left: e.pageX - el_w / 2
});
}
});
$dragging = $(e.target);
}).on("mouseup", ".draggable", function(e) {
$dragging = null;
$(this).removeAttr('unselectable').removeClass('draggable');
});
});
演示：http://jsfiddle.net/tovic/Jge9z/31/
我为这个主题创建了一个简单的插件。
// Simple JQuery Draggable Plugin
// https://plus.google.com/108949996304093815163/about
// Usage: $(selector).drags();
// Options:
// handle => your dragging handle.
// If not defined, then the whole body of the
// selected element will be draggable
// cursor => define your draggable element cursor type
// draggableClass => define the draggable class
// activeHandleClass => define the active handle class
//
// Update: 26 February 2013
// 1. Move the `z-index` manipulation from the plugin to CSS declaration
// 2. Fix the laggy effect, because at the first time I made this plugin,
// I just use the `draggable` class that's added to the element
// when the element is clicked to select the current draggable element. (Sorry about my bad English!)
// 3. Move the `draggable` and `active-handle` class as a part of the plugin option
// Next update?? NEVER!!! Should create a similar plugin that is not called `simple`!
(function($) {
$.fn.drags = function(opt) {
opt = $.extend({
handle: "",
cursor: "move",
draggableClass: "draggable",
activeHandleClass: "active-handle"
}, opt);
var $selected = null;
var $elements = (opt.handle === "") ? this : this.find(opt.handle);
$elements.css('cursor', opt.cursor).on("mousedown", function(e) {
if(opt.handle === "") {
$selected = $(this);
$selected.addClass(opt.draggableClass);
} else {
$selected = $(this).parent();
$selected.addClass(opt.draggableClass).find(opt.handle).addClass(opt.activeHandleClass);
}
var drg_h = $selected.outerHeight(),
drg_w = $selected.outerWidth(),
pos_y = $selected.offset().top + drg_h - e.pageY,
pos_x = $selected.offset().left + drg_w - e.pageX;
$(document).on("mousemove", function(e) {
$selected.offset({
top: e.pageY + pos_y - drg_h,
left: e.pageX + pos_x - drg_w
});
}).on("mouseup", function() {
$(this).off("mousemove"); // Unbind events from document
if ($selected !== null) {
$selected.removeClass(opt.draggableClass);
$selected = null;
}
});
e.preventDefault(); // disable selection
}).on("mouseup", function() {
if(opt.handle === "") {
$selected.removeClass(opt.draggableClass);
} else {
$selected.removeClass(opt.draggableClass)
.find(opt.handle).removeClass(opt.activeHandleClass);
}
$selected = null;
});
return this;
};
})(jQuery);
演示： http://tovic.github.io/dte-project/jquery-draggable/index.html
$selected = $(this).parent(); 的第 38:59 行，您将强制开发人员使用固定的 HTML 结构。您假设父元素是要移动的完整“结构”，但如果您分配一个类似于 class='draggableContainer' 的类，那么您可以执行类似 $selected = $(this).closest(".draggableContainer"); 的操作，这样您就可以使用任何 HTML 结构并且它会正常工作。总的来说， $hit 很酷，工作得非常好。 - ncubicaevent.stopPropagation()，我尝试过了，但无法停止它。我不确定应该把它放在哪里。 - ncubica这是我的贡献：
http://jsfiddle.net/g6m5t8co/1/
<!doctype html>
<html>
<head>
<style>
#container {
position:absolute;
background-color: blue;
}
#elem{
position: absolute;
background-color: green;
-webkit-user-select: none;
-moz-user-select: none;
-o-user-select: none;
-ms-user-select: none;
-khtml-user-select: none;
user-select: none;
}
</style>
<script>
var mydragg = function(){
return {
move : function(divid,xpos,ypos){
divid.style.left = xpos + 'px';
divid.style.top = ypos + 'px';
},
startMoving : function(divid,container,evt){
evt = evt || window.event;
var posX = evt.clientX,
posY = evt.clientY,
divTop = divid.style.top,
divLeft = divid.style.left,
eWi = parseInt(divid.style.width),
eHe = parseInt(divid.style.height),
cWi = parseInt(document.getElementById(container).style.width),
cHe = parseInt(document.getElementById(container).style.height);
document.getElementById(container).style.cursor='move';
divTop = divTop.replace('px','');
divLeft = divLeft.replace('px','');
var diffX = posX - divLeft,
diffY = posY - divTop;
document.onmousemove = function(evt){
evt = evt || window.event;
var posX = evt.clientX,
posY = evt.clientY,
aX = posX - diffX,
aY = posY - diffY;
if (aX < 0) aX = 0;
if (aY < 0) aY = 0;
if (aX + eWi > cWi) aX = cWi - eWi;
if (aY + eHe > cHe) aY = cHe -eHe;
mydragg.move(divid,aX,aY);
}
},
stopMoving : function(container){
var a = document.createElement('script');
document.getElementById(container).style.cursor='default';
document.onmousemove = function(){}
},
}
}();
</script>
</head>
<body>
<div id='container' style="width: 600px;height: 400px;top:50px;left:50px;">
<div id="elem" onmousedown='mydragg.startMoving(this,"container",event);' onmouseup='mydragg.stopMoving("container");' style="width: 200px;height: 100px;">
<div style='width:100%;height:100%;padding:10px'>
<select id=test>
<option value=1>first
<option value=2>second
</select>
<INPUT TYPE=text value="123">
</div>
</div>
</div>
</body>
</html>
getBoundingClientRect() 函数获取 #elem 的矩形信息，然后使用该矩形的 top/left 属性初始化 divTop/divLeft 变量！额外加分：这样你就不再需要任何预设或 style 了。 - Sz.var a = document.createElement('script'); 是什么意思？ - Bowi最基本的可拖动代码如下：
Element.prototype.drag = function(){
var mousemove = function(e){ // document mousemove
this.style.left = ( e.clientX - this.dragStartX ) + 'px';
this.style.top = ( e.clientY - this.dragStartY ) + 'px';
}.bind(this);
var mouseup = function(e){ // document mouseup
document.removeEventListener('mousemove',mousemove);
document.removeEventListener('mouseup',mouseup);
}.bind(this);
this.addEventListener('mousedown',function(e){ // element mousedown
this.dragStartX = e.offsetX;
this.dragStartY = e.offsetY;
document.addEventListener('mousemove',mousemove);
document.addEventListener('mouseup',mouseup);
}.bind(this));
this.style.position = 'absolute' // fixed might work as well
}
然后使用（非jQuery）：
document.querySelector('.target').drag();
或使用jQuery：
$('.target')[0].drag();
注意：被拖动的元素应该应用position:absolute或position:fixed以使左、上移动生效...
以下CodePen具有一些更高级的功能：dragStart、dragStop回调，追加CSS类来移除拖动时其他元素的文本选择，还具有放置特性...
请查看以下CodePen：http://codepen.io/anon/pen/VPPaEK
基本上是在需要拖动的元素上设置'mousedown'事件，然后绑定和解绑文档mousemove来处理移动。
为了为元素设置可拖动手柄
Element.prototype.drag = function( setup ){
var setup = setup || {};
var mousemove = function(e){ // document mousemove
this.style.left = ( e.clientX - this.dragStartX ) + 'px';
this.style.top = ( e.clientY - this.dragStartY ) + 'px';
}.bind(this);
var mouseup = function(e){ // document mouseup
document.removeEventListener('mousemove',mousemove);
document.removeEventListener('mouseup',mouseup);
}.bind(this);
var handle = setup.handle || this;
handle.addEventListener('mousedown',function(e){ // element mousedown
this.dragStartX = e.offsetX;
this.dragStartY = e.offsetY;
document.addEventListener('mousemove',mousemove);
document.addEventListener('mouseup',mouseup);
handle.classList.add('dragging');
}.bind(this));
handle.classList.add('draggable');
this.style.position = 'absolute' // fixed might work as well
}
以上代码的用法如下：
var setup = {
handle : document.querySelector('.handle')
};
document.querySelector('.box').drag(setup);
现在的问题是，在拖动时，可拖动元素内的文本令人恼火地被选择了，但却毫无用处...
这就是为什么我们已经向该元素添加了draggable和dragging类，它们将取消这种不需要的行为，并添加一个移动光标，以显示此元素是可拖动的。
.draggable{
cursor: move;
position: fixed;
}
.draggable.dragging{
user-select: none;
}
现在我们有了可拖动的元素，有时候需要调用各种不同的事件。
setup.ondraginit // this is called when setting up the draggable
setup.ondragstart // this is called when mouse is down on the element
setup.ondragend // this is called when mouse is released (after dragging)
setup.ondrag // this is called while the element is being dragged
Element.prototype.drag = function( setup ){
var setup = setup || {};
var mousemove = function(e){ // document mousemove
this.style.left = ( e.clientX - this.dragStartX ) + 'px';
this.style.top = ( e.clientY - this.dragStartY ) + 'px';
setup.ondrag && setup.ondrag(e); // ondrag event
}.bind(this);
var mouseup = function(e){ // document mouseup
document.removeEventListener('mousemove',mousemove);
document.removeEventListener('mouseup',mouseup);
handle.classList.remove('dragging');
setup.ondragend && setup.ondragend(e); // ondragend event
}.bind(this);
var handle = setup.handle || this;
handle.addEventListener('mousedown',function(e){ // element mousedown
this.dragStartX = e.offsetX;
this.dragStartY = e.offsetY;
document.addEventListener('mousemove',mousemove);
document.addEventListener('mouseup',mouseup);
handle.classList.add('dragging');
setup.ondragstart && setup.ondragstart(e); // ondragstart event
}.bind(this));
handle.classList.add('draggable');
setup.ondraginit && setup.ondraginit(e); // ondraginit event
}
而要使用它：
var setup = {
handle : document.querySelector('.handle'),
ondragstart : e => { console.log('drag has started!'); },
ondrag : e => { console.log('drag!'); },
ondragend : e => { console.log('drag has ended!'); }
};
document.querySelector('.box').drag(setup);
请注意，e.target是指向我们可拖动元素的引用。
function endMove() {
$(this).removeClass('movable');
}
function startMove() {
$('.movable').on('mousemove', function(event) {
var thisX = event.pageX - $(this).width() / 2,
thisY = event.pageY - $(this).height() / 2;
$('.movable').offset({
left: thisX,
top: thisY
});
});
}
$(document).ready(function() {
$("#containerDiv").on('mousedown', function() {
$(this).addClass('movable');
startMove();
}).on('mouseup', function() {
$(this).removeClass('movable');
endMove();
});
});
CSS
#containerDiv {
background:#333;
position:absolute;
width:200px;
height:100px;
}
像jQueryUI一样拖动： JsFiddle
你可以从任何点开始拖动元素而不会出现奇怪的居中问题。
$(document).ready(function() {
var $body = $('body');
var $target = null;
var isDraggEnabled = false;
$body.on("mousedown", "div", function(e) {
$this = $(this);
isDraggEnabled = $this.data("draggable");
if (isDraggEnabled) {
if(e.offsetX==undefined){
x = e.pageX-$(this).offset().left;
y = e.pageY-$(this).offset().top;
}else{
x = e.offsetX;
y = e.offsetY;
};
$this.addClass('draggable');
$body.addClass('noselect');
$target = $(e.target);
};
});
$body.on("mouseup", function(e) {
$target = null;
$body.find(".draggable").removeClass('draggable');
$body.removeClass('noselect');
});
$body.on("mousemove", function(e) {
if ($target) {
$target.offset({
top: e.pageY - y,
left: e.pageX - x
});
};
});
});
这是我的。 http://jsfiddle.net/pd1vojsL/
一个 div 内有 3 个可拖动的按钮，拖动受该 div 的限制。
<div id="parent" class="parent">
<button id="button1" class="button">Drag me</button>
<button id="button2" class="button">Drag me</button>
<button id="button3" class="button">Drag me</button>
</div>
<div id="log1"></div>
<div id="log2"></div>
需要 JQuery（仅限）：
$(function() {
$('.button').mousedown(function(e) {
if(e.which===1) {
var button = $(this);
var parent_height = button.parent().innerHeight();
var top = parseInt(button.css('top')); //current top position
var original_ypos = button.css('top','').position().top; //original ypos (without top)
button.css({top:top+'px'}); //restore top pos
var drag_min_ypos = 0-original_ypos;
var drag_max_ypos = parent_height-original_ypos-button.outerHeight();
var drag_start_ypos = e.clientY;
$('#log1').text('mousedown top: '+top+', original_ypos: '+original_ypos);
$(window).on('mousemove',function(e) {
//Drag started
button.addClass('drag');
var new_top = top+(e.clientY-drag_start_ypos);
button.css({top:new_top+'px'});
if(new_top<drag_min_ypos) { button.css({top:drag_min_ypos+'px'}); }
if(new_top>drag_max_ypos) { button.css({top:drag_max_ypos+'px'}); }
$('#log2').text('mousemove min: '+drag_min_ypos+', max: '+drag_max_ypos+', new_top: '+new_top);
//Outdated code below (reason: drag contrained too early)
/*if(new_top>=drag_min_ypos&&new_top<=drag_max_ypos) {
button.css({top:new_top+'px'});
}*/
});
$(window).on('mouseup',function(e) {
if(e.which===1) {
//Drag finished
$('.button').removeClass('drag');
$(window).off('mouseup mousemove');
$('#log1').text('mouseup');
$('#log2').text('');
}
});
}
});
});
我看到的以上内容非常复杂......
以下是一些可供参考的代码。
$("#box").on({
mousedown:function(e)
{
dragging = true;
dragX = e.clientX - $(this).position().left;
//To calculate the distance between the cursor pointer and box
dragY = e.clientY - $(this).position().top;
},
mouseup:function(){dragging = false;},
//If not set this on/off,the move will continue forever
mousemove:function(e)
{
if(dragging)
$(this).offset({top:e.clientY-dragY,left:e.clientX-dragX});
}
})
可以将dragging、dragX和dragY作为全局变量。
这是一个关于此问题的简单演示，但该方法存在一些错误。
如果您现在需要，可以在此处查看示例。
我有一个简单版本的代码，完全不需要使用任何 JQuery，而且实现起来非常容易！
// add 'draggable-object' as an attribute to your div element
var dragDiv = document.querySelector("div[draggable-object]");
// add the '-header' to the header element of the draggable div if you want the user to press a specific part of the element to drag it
var dragDivHeader = document.querySelector("div[draggable-object-header]");
// function for getting the mouse offset from the div position
function getMouseOffset()
{
var e = window.event;
var divX = parseInt(getComputedStyle(dragDiv).left);
var divY = parseInt(getComputedStyle(dragDiv).top);
return {
X: e.clientX - divX,
Y: e.clientY - divY,
};
}
// variable for storing mouse offset from div element position
var mouseOffset = null;
// enable the mouse events, but on the document itself for easy dragging
function enableMouseDrag()
{
document.onmouseup = disableMouseDrag;
document.onmousemove = dragDivWithMouse;
mouseOffset = getMouseOffset(); // get the mouse offset only when pressing down once
}
// drag div with mouse
function dragDivWithMouse()
{
var e = window;
// get the new x/y position of the draggable div element
var newX = e.clientX - mouseOffset.X;
var newY = e.clientY - mouseOffset.Y;
// sets the new element position while also keeping it inside the document page without more lines of code
dragDiv.style.left = Math.max(2, Math.min(newX, document.documentElement.clientWidth - dragDiv.offsetWidth - 2)) + "px";
dragDiv.style.top = Math.max(2, Math.min(newY, document.documentElement.clientHeight - dragDiv.offsetHeight - 2)) + "px";
}
// disable the mouse events for the document itself
function disableMouseDrag()
{
document.onmouseup = null;
document.onmousemove = null;
}
// add the enableMouseDrag event callback to the div itself, or specify its header if you want
dragDiv.onmousedown = enableMouseDrag;
// dragDivHeader.onmousedown = enableMouseDrag;
我希望这能成为一个简单易用的解决方案。
$(document).ready(function() {
var $startAt = null;
$(document.body).live("mousemove", function(e) {
if ($startAt) {
$("#someDiv").offset({
top: e.pageY,
left: $("#someDiv").position().left-$startAt+e.pageX
});
$startAt = e.pageX;
}
});
$("#someDiv").live("mousedown", function (e) {$startAt = e.pageX;});
$(document.body).live("mouseup", function (e) {$startAt = null;});
});
mouseleave事件来扩展代码，例如$("body").mouseleave(function(e) { $dragging = null; })，以便在浏览器窗口外释放按下的按钮。 - rabudde