JS拖曳盒子案例

让我为大家带来一个小案例吧！

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			* {
				margin: 0;
				padding: 0;
			}
			.box1 {
				width: 100px;
				height: 100px;
				background-color: black;
				margin-bottom: 10px;
				position: relative;
				left: 0;
				top: 0;
			}
			.box2 {
				width: 100px;
				height: 100px;
				background-color: pink;
				margin-bottom: 10px;
				margin-left: 200px;
			}
			.box3 {
				width: 100px;
				height: 100px;
				background-color: orange;
				margin-top: 120px;
				margin-left: 200px;
			}
		</style>
	</head>
	<body>
		<div class="box1"></div>
		<div class="box2"></div>
		<div class="box3"></div>
	</body>
	<script>
		//获取要移动的盒子
	 	var div = document.querySelector(".box1")
		//获取其他2个盒子
		var div1=document.querySelector(".box2")
		var div2=document.querySelector(".box3")
		div.onmousedown = function(e){
			//获取盒子距离页面多少
			var divX =div.offsetLeft
			var divY =div.offsetTop
			//获取盒子点击的xy坐标
			var downX =e.clientX
			var downY =e.clientY
			document.onmousemove=function(e){
			console.log(e);
			// if(div.offsetLeft<1){
			// 	alert("超出")
			// }
			//获取盒子点击的地方距离document点击的坐标的差
			var moveX =e.clientX - downX
			var moveY =e.clientY - downY
			//获取移动鼠标想放哪放哪
			// div.style.left =divX+moveX+"px"
			// div.style.top =divY+moveY+"px"
			//这个的中心点在中间
			div.style.left =e.clientX - div.offsetWidth/2+"px"
			div.style.top =e.clientY - div.offsetHeight/2+"px"
			//拿他们的宽高去判断坐标
			if(e.clientX<div1.offsetWidth+div.offsetWidth/2+200&&e.clientX>div1.offsetWidth+div.offsetWidth/2&&e.clientY>div1.offsetTop/2&&e.clientY<div1.offsetTop*2+40){
				console.log(div1.offsetTop);
				div1.style.backgroundColor="green"
				}else{
					div1.style.backgroundColor="pink"
				}
				//拿他们的距离去判断
			 if(e.clientX<div2.offsetWidth+div.offsetWidth/2+200&&e.clientX>div1.offsetWidth+div.offsetWidth/2&&e.clientY>div2.offsetTop-div.offsetHeight/2&&e.clientY<div2.offsetTop+div.offsetHeight+div.offsetHeight/2){
				div2.style.backgroundColor="blue"
				}else {
					div2.style.backgroundColor="orange"
				}
			}
		}
		//如果按起就不动
		div.onmouseup = function(){
			document.onmousemove = null
		}
	</script>
</html>