<!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>
.box {
position: fixed;
border: 1px solid #000;
background: rgba(0, 0, 0, .3);
}
#list {
margin: 0;
padding: 0;
list-style: none;
}
#list li {
float: left;
margin: 10px;
width: 100px;
height: 100px;
background: green;
}
</style>
</head>
<body>
<ul id="list">
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
<script>
{
let lists = document.querySelectorAll("#list li");
// 框选
let startMouse = {};
let el;
let move = (e)=>{
let nowMouse = {
x: e.clientX,
y: e.clientY
};
let dis = {
x: nowMouse.x - startMouse.x,
y: nowMouse.y - startMouse.y
};
el.style.left = Math.min(startMouse.x,nowMouse.x) + "px";
el.style.top = Math.min(startMouse.y,nowMouse.y) + "px";
el.style.width = Math.abs(dis.x) + "px";
el.style.height = Math.abs(dis.y) + "px";
lists.forEach(item=>{
if(boom(el,item)){
item.style.background = "red";
} else {
item.style.background = "green";
}
});
}
document.addEventListener("mousedown",(e)=>{
el = document.createElement("div")
startMouse = {
x: e.clientX,
y: e.clientY
}
el.className = "box";
document.body.appendChild(el);
document.addEventListener("mousemove",move);
document.addEventListener("mouseup",()=>{
document.removeEventListener("mousemove",move);
el.remove();
},{once:true});
e.preventDefault();
});
}
function boom(el,el2){
let rectEl1 = el.getBoundingClientRect();
let rectEl2 = el2.getBoundingClientRect();
if(rectEl1.right < rectEl2.left
|| rectEl2.right < rectEl1.left
|| rectEl1.bottom < rectEl2.top
|| rectEl2.bottom < rectEl1.top){
return false;
}
return true;
}
</script>
</body>
</html>
