demo：
<!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{width:200px;height: 300px;background: #ccc;position: absolute;left:0;top:0;display: none}
.box ul{margin: 0}
</style>
</head>
<body>
<!-- <a href="http://www.baidu.com">21321312</a> -->
<class = div "Box">
<Li> Option 3 </ li>
<Li> option. 1 </ Li>
<UL>
<Li> Option 2 </ li>
<li> option. 4 </ Li>
</ UL>
</ div>
</ body>
<Script> var Obox document.querySelector = (. "Box" )
Document. the oncontextmenu = function (eve) {// oncontextmenu event fires and open the context menu when the user right-click in the element.
var E = || Eve the window.event;
obox.style.display = "Block" ; // return to false; // cancel the default event stopDefault (E);
obox.style.left = e.offsetX + "PX" ;
Obox .style.top = E.
= function(){
obox.style.display = "none"
}
function stopDefault(e){
if(e.preventDefault){
e.preventDefault() //IE
}else{
e.returnValue = false; //GOOGLE
}
} //封装函数
</script>
</html>