<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>鼠标拖拽多选功能</title>
<script src="https://cdn.bootcss.com/jquery/1.10.2/jquery.min.js"></script>
<style type="text/css">
*{
box-sizing:border-box;
}
ul{
500px;
height:auto;
margin:0;
padding:20px;
font-size: 0;
/*需设置定位*/
position:relative;
}
li{
70px;
height:70px;
margin:10px;
padding:0;
display:inline-block;
vertical-align: top;
font-size: 13px;
border:1px solid #d9d9d9;
}
#moveSelected{
position:absolute;
background-color: blue;
opacity:0.3;
border:1px dashed #d9d9d9;
top:0;
left:0;
}
.selected{
background-color: pink;
}
</style>
</head>
<body>
<ul class="list">
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
<li>10</li>
<li>11</li>
<li>12</li>
<li>13</li>
<li>14</li>
<li>15</li>
<li>16</li>
<li>17</li>
<li>18</li>
<li>19</li>
<li>20</li>
<li>21</li>
<li>22</li>
<!-- 鼠标拖拽出的遮罩 (定位为 position:absolute)-->
<!-- 遮罩最好是在绑定了mouseover事件的元素内部,并且不要阻止遮罩的冒泡事件。这样鼠标移到了遮罩上面,依然可以利用冒泡执行父元素的mouseover事件,就不会出现遮罩只能扩大,不能缩小的情况了(亲自试过) -->
<div id="moveSelected"></div>
</ul>
</body>
</html>
<script type="text/javascript">
$(document).ready(function(){
let moveSelected=$('#moveSelected')[0];
let flag=false;//是搜开启拖拽的标志
let oldLeft=0;//鼠标按下时的left,top
let oldTop=0;
let selectedList=[];//拖拽多选选中的块集合
// 鼠标按下时开启拖拽多选,将遮罩定位并展现
$(".list").mousedown(function(event) {
flag=true;
moveSelected.style.top=event.pageY+'px';
moveSelected.style.left=event.pageX+'px';
oldLeft=event.pageX;
oldTop=event.pageY;
event.preventDefault(); // 阻止默认行为
event.stopPropagation(); // 阻止事件冒泡
});
// 鼠标移动时计算遮罩的位置,宽 高
$(".list").mousemove(function(event) {
if(!flag) return;//只有开启了拖拽,才进行mouseover操作
if(event.pageX<oldLeft){//向左拖
moveSelected.style.left=event.pageX+'px';
moveSelected.style.width=(oldLeft-event.pageX)+'px';
}else{
moveSelected.style.width=(event.pageX-oldLeft)+'px';
}
if(event.pageY<oldTop){//向上
moveSelected.style.top=event.pageY+'px';
moveSelected.style.height=(oldTop-event.pageY)+'px';
}else{
moveSelected.style.height=(event.pageY-oldTop)+'px';
}
event.preventDefault(); // 阻止默认行为
event.stopPropagation(); // 阻止事件冒泡
});
//鼠标抬起时计算遮罩的right 和 bottom,找出遮罩覆盖的块,关闭拖拽选中开关,清除遮罩数据
$(".list").mouseup(function(event) {
moveSelected.style.bottom=Number(moveSelected.style.top.split('px')[0])+Number(moveSelected.style.height.split('px')[0]) + 'px';
moveSelected.style.right=Number(moveSelected.style.left.split('px')[0])+Number(moveSelected.style.width.split('px')[0])+'px';
findSelected();
flag=false;
clearDragData();
event.preventDefault(); // 阻止默认行为
event.stopPropagation(); // 阻止事件冒泡
});
$(".list").mouseleave(function(event) {
flag=false;
moveSelected.style.width=0;
moveSelected.style.height=0;
moveSelected.style.top=0;
moveSelected.style.left=0;
event.preventDefault(); // 阻止默认行为
event.stopPropagation(); // 阻止事件冒泡
});
function findSelected(){
let blockList=$('.list').find('li');
for(let i=0;i<blockList.length;i++){
//计算每个块的定位信息
let left=$(blockList[i]).offset().left;
let right=$(blockList[i]).width()+left;
let top=$(blockList[i]).offset().top;
let bottom=$(blockList[i]).height()+top;
//判断每个块是否被遮罩盖住(即选中)
let leftFlag=moveSelected.style.left.split('px')[0]<=left && left<=moveSelected.style.right.split('px')[0];
let rightFlag=moveSelected.style.left.split('px')[0]<=right && right<=moveSelected.style.right.split('px')[0];
let topFlag=moveSelected.style.top.split('px')[0]<=top && top<=moveSelected.style.bottom.split('px')[0];
let bottomFlag=moveSelected.style.top.split('px')[0]<=bottom && bottom<=moveSelected.style.bottom.split('px')[0];
if((leftFlag || rightFlag) && (topFlag || bottomFlag)){
selectedList.push(blockList[i]);
$(blockList[i]).addClass('selected');
}
}
console.log(selectedList);
}
function clearDragData(){
moveSelected.style.width=0;
moveSelected.style.height=0;
moveSelected.style.top=0;
moveSelected.style.left=0;
moveSelected.style.bottom=0;
moveSelected.style.right=0;
}
});
</script>