<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> textarea{font-size:1em; 500px; height:100px;} </style> </head> <body> <textarea id="target"></textarea> <p><button id="btn">插入话题</button></p> </body> <script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.js"></script> <script> var $ = function(id){ return document.getElementById(id); }; $("btn").onclick = function(){ var con = "请在这里输入自定义话题"; //转载文字 $("target").innerHTML += "#"+con+"#"; var l = $("target").innerHTML.length; //创建选择区域 if($("target").createTextRange){//IE浏览器 var range = $("target").createTextRange(); range.moveEnd("character",-l) //range.moveStart("character",-l) range.moveEnd("character",l-1); range.moveStart("character", l-1-con.length); range.select(); }else{ $("target").setSelectionRange(l-1-con.length,l-1); $("target").focus(); } }; </script> </html>