内容简介：拖拽
- DataTransfer 对象：退拽对象用来传递的媒介，使用一般为Event.dataTransfer。
-
draggable 属性：就是标签元素要设置draggable=true，否则不会有效果，例如：
列表1
-
ondragstart 事件：当拖拽元素开始被拖拽的时候触发的事件，此事件作用在被拖曳元素上
- ondragenter 事件：当拖曳元素进入目标元素的时候触发的事件，此事件作用在目标元素上
- ondragover 事件：拖拽元素在目标元素上移动的时候触发的事件，此事件作用在目标元素上
- ondrop 事件：被拖拽的元素在目标元素上同时鼠标放开触发的事件，此事件作用在目标元素上
- ondragend 事件：当拖拽完成后触发的事件，此事件作用在被拖曳元素上
- Event.preventDefault() 方法：阻止默认的些事件方法等执行。在ondragover中一定要执行preventDefault()，否则ondrop事件不会被触发。另外，如果是从其他应用软件或是文件中拖东西进来，尤其是图片的时候，默认的动作是显示这个图片或是相关信息，并不是真的执行drop。此时需要用用document的ondragover事件把它直接干掉。
-
Event.effectAllowed 属性：就是拖拽的效果。
<divclass="dustbin"><br/>垃<br/>圾<br/>箱</div> <divclass="dragbox"> <divclass="draglist"title="拖拽我"draggable="true">列表1</div> <divclass="draglist"title="拖拽我"draggable="true">列表2</div> <divclass="draglist"title="拖拽我"draggable="true">列表3</div> <divclass="draglist"title="拖拽我"draggable="true">列表4</div> <divclass="draglist"title="拖拽我"draggable="true">列表5</div> <divclass="draglist"title="拖拽我"draggable="true">列表6</div> </div> <divclass="dragremind"></div>
JS代码如下：
var $ = function(selector){
/*简单的选择器方法*/
...
};
var eleDustbin = $(".dustbin")[0], eleDrags = $(".draglist"), lDrags = eleDrags.length, eleRemind = $(".dragremind")[0], eleDrag = null;
for (var i=0; i<lDrags; i+=1) {
eleDrags[i].onselectstart = function(){
return false;
};
eleDrags[i].ondragstart = function(ev){
/*拖拽开始*/
//拖拽效果
ev.dataTransfer.effectAllowed = "move";
ev.dataTransfer.setData("text", ev.target.innerHTML);
ev.dataTransfer.setDragImage(ev.target, 0, 0);
eleDrag = ev.target;
return true;
};
eleDrags[i].ondragend = function(ev){
/*拖拽结束*/
ev.dataTransfer.clearData("text");
eleDrag = null;
return false
};
}
eleDustbin.ondragover = function(ev){
/*拖拽元素在目标元素头上移动的时候*/
ev.preventDefault();
return true;
};
eleDustbin.ondragenter = function(ev){
/*拖拽元素进入目标元素头上的时候*/
this.style.color = "#ffffff";
return true;
};
eleDustbin.ondrop = function(ev){
/*拖拽元素进入目标元素头上，同时鼠标松开的时候*/
if (eleDrag) {
eleRemind.innerHTML = '<strong>"' + eleDrag.innerHTML + '"</strong>被扔进了垃圾箱';
eleDrag.parentNode.removeChild(eleDrag);
}
this.style.color = "#000000";
return false;
};
完整例子2
<!DOCTYPE html>
<html>
<head>
<metacharset="UTF-8">
<title></title>
</head>
<body>
<divid="demo1">
<ulclass="panel-list">
<liclass="panel-item"></li>
<liclass="panel-item"></li>
<liclass="panel-item"></li>
<liclass="panel-item"></li>
<liclass="panel-item"></li>
</ul>
<h2>拖拽下面的方块到上面任意容器中</h2>
<!-- 设置draggable使元素成为可拖拽元素 -->
<spanclass="movable"id="demo1-src"draggable="true"></span>
<style>
#demo1 {
margin: 20px;
}
#demo1 .panel-list {
overflow: hidden;
list-style: none;
margin: 0;
padding: 0;
}
#demo1 .panel-item {
float: left;
margin-right: 30px;
width: 100px;
height: 100px;
background: #ddd;
border: 1px solid #ddd;
}
#demo1-src {
display: inline-block;
width: 50px;
height: 50px;
background: purple;
}
#demo1 .over {
border: 1px dashed #000;
-webkit-transform: scale(0.8, 0.8);
}
</style>
<script>
(function(){
var dnd = {
// 初始化
init: function(){
var me = this;
me.src = document.querySelector('#demo1-src');
me.panelList = document.querySelector('.panel-list');
// 为拖拽源监听dragstart,设置关联数据
me.src.addEventListener('dragstart', me.onDragStart, false);
// 拖拽鼠标移入元素,在拖放目标上设置视觉反馈
me.panelList.addEventListener('dragenter', me.onDragEnter, false);
// 取消元素dragover默认行为,使其可拖放
me.panelList.addEventListener('dragover', me.onDragOver, false);
// 拖拽移出元素,清除视觉反馈
me.panelList.addEventListener('dragleave', me.onDragLeave, false);
// 鼠标释放,在拖放目标上接收数据并处理
me.panelList.addEventListener('drop', me.onDrop, false);
},
onDragStart: function(e){
console.log(e)
e.dataTransfer.setData('text/plain', 'demo1-src');
},
onDragEnter: function(e){
if (e.target.classList.contains('panel-item')) {
e.target.classList.add('over');
}
},
onDragLeave: function(e){
if (e.target.classList.contains('panel-item')) {
e.target.classList.remove('over');
}
},
onDragOver: function(e){
e.preventDefault();
},
onDrop: function(e){
var id = e.dataTransfer.getData('text/plain');
var src = document.getElementById(id);
var target = e.target;
if (target.classList.contains('panel-item')) {
target.appendChild(src);
target.classList.remove('over');
}
}
};
dnd.init();
}());
</script>
</div>
</body>
</html>
用JavaScript事件方法
原理
①鼠标按下+鼠标移动 → 拖拽 ②鼠标松开 → 无拖拽 ③鼠标偏移 → 拖拽距离 ① onmousedown + onmousemove → startDrag() ② onmouseup → stopDrag() ③ ……
关键点就是让鼠标的偏移值赋给拖拽对象。
js实例
var params = {
left: 0,
top: 0,
currentX: 0,
currentY: 0,
flag: false
};
//获取相关CSS属性
var getCss = function(o,key){
return o.currentStyle? o.currentStyle[key] : document.defaultView.getComputedStyle(o,false)[key];
};
//拖拽的实现
var startDrag = function(bar, target, callback){
if(getCss(target, "left") !== "auto"){
params.left = getCss(target, "left");
}
if(getCss(target, "top") !== "auto"){
params.top = getCss(target, "top");
}
//o是移动对象
bar.onmousedown = function(event){
params.flag = true;
if(!event){
event = window.event;
//防止IE文字选中
bar.onselectstart = function(){
return false;
}
}
var e = event;
params.currentX = e.clientX;
params.currentY = e.clientY;
};
document.onmouseup = function(){
params.flag = false;
if(getCss(target, "left") !== "auto"){
params.left = getCss(target, "left");
}
if(getCss(target, "top") !== "auto"){
params.top = getCss(target, "top");
}
};
document.onmousemove = function(event){
var e = event ? event: window.event;
if(params.flag){
var nowX = e.clientX, nowY = e.clientY;
var disX = nowX - params.currentX, disY = nowY - params.currentY;
target.style.left = parseInt(params.left) + disX + "px";
target.style.top = parseInt(params.top) + disY + "px";
}
if (typeof callback == "function") {
callback(parseInt(params.left) + disX, parseInt(params.top) + disY);
}
}
};
HTML/CSS
<styletype="text/css">
#box{position:absolute; left:100px; top:100px; padding:5px; background:#f0f3f9; font-size:12px; -moz-box-shadow:2px 2px 4px #666666; -webkit-box-shadow:2px 2px 4px #666666;}
#main{border:1px solid #a0b3d6; background:white;}
#bar{line-height:24px; background:#beceeb; border-bottom:1px solid #a0b3d6; padding-left:5px; cursor:move;}
#content{width:420px; height:250px; padding:10px 5px;}
</style>
<divid="box">
<divid="main">
<divid="bar">拖拽</div>
<divid="content">
内容……
</div>
</div>
</div>
<scripttype="text/javascript">
var oBox = document.getElementById("box");//被拖拽的对象
var oBar = document.getElementById("bar");//触发拖拽的对象
startDrag(oBar, oBox);
</script>
拖拽实例
<!doctype html>
<htmllang="en">
<head>
<metacharset="UTF-8">
<metaname="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<metahttp-equiv="X-UA-Compatible"content="ie=edge">
<title>drag</title>
<style>
.div1{width: 1000px;height: 100px;background: #eeeeee;position: relative;margin: 0 auto;}
.div2{width: 100px;height: 100px;background: #dddddd;position: absolute;top: 0px;left: 0px;cursor: pointer;}
</style>
</head>
<body>
<divclass="div1">
<divclass="div2"></div>
</div>
<script>
var params = {
left: 0,
top: 0,
currentX: 0, //点击的时候记录鼠标坐标
currentY: 0,
flag: false
};
var parentPara = { //移动的范围
height:0,
width:0
};
var son = {
width:0,
height:0,
}
//获取相关CSS属性
var getCss = function(o,key){
return o.currentStyle? o.currentStyle[key] : document.defaultView.getComputedStyle(o,false)[key];
};
//拖拽的实现
var startDrag = function(bar, target, parentBox,callback){
if(getCss(target, "left") !== "auto"){
params.left = getCss(target, "left");
}
if(getCss(target, "top") !== "auto"){
params.top = getCss(target, "top");
}
//父盒子宽高
if(parentBox){
parentPara.width = parentBox.scrollWidth - target.scrollWidth;
parentPara.height = parentBox.scrollHeight - target.scrollHeight;
console.log(parentPara);
}
//子盒子宽高
//o是移动对象
bar.onmousedown = function(event){
params.flag = true;
if(!event){
event = window.event;
//防止IE文字选中
bar.onselectstart = function(){
return false;
}
}
var e = event;
params.currentX = e.clientX;
params.currentY = e.clientY;
};
document.onmouseup = function(){
params.flag = false;
if(getCss(target, "left") !== "auto"){
params.left = getCss(target, "left");
}
if(getCss(target, "top") !== "auto"){
params.top = getCss(target, "top");
}
};
document.onmousemove = function(event){
var e = event ? event: window.event;
if(params.flag){
var nowX = e.clientX, nowY = e.clientY; //鼠标位置
var disX = nowX - params.currentX, disY = nowY - params.currentY; //移动的距离
var succX = parseInt(params.left) + disX, succY = parseInt(params.top) + disY;
if(succX<=0){succX =0 }
if(succY<=0){succY =0 }
if(succX>=parentPara.width){succX =parentPara.width }
if(succY>=parentPara.height){succY =parentPara.height }
target.style.left = succX + "px";
target.style.top = succY + "px";
}
if (typeof callback == "function") {
callback(parseInt(params.left) + disX, parseInt(params.top) + disY);
}
}
};
var oBox = document.querySelector(".div2");//被拖拽的对象
var oBar = document.querySelector(".div2");//触发拖拽的对象
var oMain = document.querySelector(".div1");//父盒子
startDrag(oBar, oBox, oMain);
</script>
</body>
</html>
结合滚轮待修改
<!doctype html>
<htmllang="en">
<head>
<metacharset="UTF-8">
<metaname="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<metahttp-equiv="X-UA-Compatible"content="ie=edge">
<title>drag</title>
<style>
.div1{width: 1000px;height: 100px;background: #eeeeee;position: relative;margin: 0 auto;}
.div2{width: 100px;height: 100px;background: #dddddd;position: absolute;top: 0px;left: 0px;cursor: pointer;}
</style>
</head>
<body>
<divclass="div1">
<divclass="div2"></div>
</div>
<script>
var a = 0;
var params = {
left: 0,
top: 0,
currentX: 0, //点击的时候记录鼠标坐标
currentY: 0,
flag: false
};
var parentPara = { //移动的范围
height:0,
width:0
};
var son = {
width:0,
height:0,
}
//获取相关CSS属性
var getCss = function(o,key){
return o.currentStyle? o.currentStyle[key] : document.defaultView.getComputedStyle(o,false)[key];
};
//拖拽的实现
var startDrag = function(bar, target, parentBox,callback){
if(getCss(target, "left") !== "auto"){
params.left = getCss(target, "left");
}
if(getCss(target, "top") !== "auto"){
params.top = getCss(target, "top");
}
//可移动宽高
if(parentBox){
parentPara.width = parentBox.scrollWidth - target.scrollWidth;
parentPara.height = parentBox.scrollHeight - target.scrollHeight;
}
//子盒子宽高
//o是移动对象
bar.onmousedown = function(event){
params.flag = true;
if(!event){
event = window.event;
//防止IE文字选中
bar.onselectstart = function(){
return false;
}
}
var e = event;
params.currentX = e.clientX;
params.currentY = e.clientY;
};
document.onmouseup = function(){
params.flag = false;
if(getCss(target, "left") !== "auto"){
params.left = getCss(target, "left");
}
if(getCss(target, "top") !== "auto"){
params.top = getCss(target, "top");
}
};
document.onmousemove = function(event){
var e = event ? event: window.event;
if(params.flag){
var nowX = e.clientX, nowY = e.clientY; //鼠标位置
var disX = nowX - params.currentX, disY = nowY - params.currentY; //移动的距离
var succX = parseInt(params.left) + disX, succY = parseInt(params.top) + disY;
succX = succX<=0 ? succX = 0 :succX;
succY = succY<=0 ? succY = 0 :succY;
succX = succX>=parentPara.width ? succX =parentPara.width : succX;
succY = succY>=parentPara.height ? succY = parentPara.height : succY;
a = parseInt(succX/50)
target.style.left = succX + "px";
target.style.top = succY + "px";
}
if (typeof callback == "function") {
callback(parseInt(params.left) + disX, parseInt(params.top) + disY);
}
}
};
var oBox = document.querySelector(".div2");//被拖拽的对象
var oBar = document.querySelector(".div2");//触发拖拽的对象
var oMain = document.querySelector(".div1");//父盒子
startDrag(oBar, oBox, oMain);
</script>
<script>
window.onload = function(){
var odiv1 = document.querySelector('.div1');
var explorer = navigator.userAgent;
if (explorer.indexOf("Firefox") >= 0 ) {
odiv1.addEventListener('DOMMouseScroll',wheel)//火狐
} else if(explorer.indexOf('Trident')>-1&&explorer.indexOf('rv:11')>-1){
odiv1.addEventListener('mousewheel',wheel)//ie
}else {
odiv1.addEventListener('wheel',wheel)//谷歌
}
function wheel(ev){
var e = ev || window.event;
if (explorer.indexOf("Firefox") >= 0) {
a+=e.detail/3; //火狐
} else{
a+=e.wheelDelta/120; //谷歌
}
a = a<=0 ? a =0 : a
a = a>=parentPara.width/50 ? a =parentPara.width/50 : a
params.left = a*50;
oBox.style.left = a*50 + "px";
}
}
</script>
</body>
</html>
jQuery拖拽
<!DOCTYPE html>
<htmllang="en">
<head>
<metacharset="UTF-8">
<title>判断拖拽速度</title>
</head>
<body>
<styletype="text/css">
#drag{width:400px;height:300px; background: #999;cursor:move;position:absolute;top:300px;left:300px;border:solid 1px #ccc;}
</style>
<scriptsrc="js/jquery-2.0.3.min.js"></script>
<script>
$(function(){
var dragging = false;
var iX, iY;
var main = {X:0,Y:0};
var newmain = {X:0,Y:0,X2:0,Y2:0}; //2为去正后的数
var data1,data2;
$("#drag").mousedown(function(e){
data1 = new Date().getTime();//起始时间
dragging = true;
main.X = $(this).offset().left;
main.Y = $(this).offset().top;
iX = e.clientX - main.X;
iY = e.clientY - main.Y;
this.setCapture && this.setCapture();
return false;
});
document.onmousemove = function(e){
if (dragging) {
var e = e || window.event;
var oX = e.clientX - iX;
var oY = e.clientY - iY;
$("#drag").css({"left":oX + "px", "top":oY + "px"});
return false;
}
};
$(document).mouseup(function(e){
dragging = false;
data2 = new Date().getTime(); //释放的时间
//拖动的速度
newmain.X = ($("#drag").offset().left - main.X)/(data2-data1);
newmain.Y = ($("#drag").offset().top - main.Y)/(data2-data1);
//速度取正
newmain.X2 = newmain.X < 0 ? -newmain.X : newmain.X;
newmain.Y2 = newmain.Y < 0 ? -newmain.Y : newmain.Y;
//判断那个方向
var direction = newmain.X2 > newmain.Y2 ? "X" : "Y";
if (direction == "X") {
direction = newmain.X < 0 ? "X2" : "X" //左右判断
}
if (direction == "Y") {
direction = newmain.Y < 0 ? "Y2" : "Y" //上下判断
}
console.log(direction + "----------X2：左边；X：右边；Y2：上边；Y：下边")
// 如果左右快速拖动
if (newmain.X2 > 1) {
console.log("快速的朝"+ direction +"方向拖动！！！")
var num = direction == "X" ? 300 : -300
$("#drag").animate({left:main.Y + num},500)
}else if (newmain.Y2 > 1) { //如果快速上下移动
console.log("快速的朝"+ direction +"方向拖动！！！")
var num = direction == "Y" ? 300 : -300
$("#drag").animate({top:main.X + num},500)
}else {
$("#drag").animate({top:main.X,left:main.Y},500) //速度太慢，返回原点回去
console.log('回去')
}
})
})
</script>
<divid="drag">
</div>
</body>
</html>
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