js按ctrl+enter换行，让可编辑的div换行，并获取输入焦点光标

<div id="inputTxtArea" contenteditable="true"></div>

$(document).keydown(function (e) {
    var e = e || window.event, ec = e.keyCode || e.which;
    if (!e.ctrlKey && 13 == ec) {
        //console.log('发送');
        sendMsgTal();
        return false;
    }
    if (e.ctrlKey && 13 == ec) {
        //console.log('换行');
        if (browserType() == "IE" || browserType() == "Edge") {
            $("#inputTxtArea").append("<div></div>");
        }
        else if (browserType() == "FF") {
            $("#inputTxtArea").append("<br/><br/>");
        } else {
            $("#inputTxtArea").append("<div><br/></div>");
        }
        //设置输入焦点
        var o = document.getElementById("inputTxtArea").lastChild;            
        var textbox = document.getElementById('inputTxtArea');
        var sel = window.getSelection();
        var range = document.createRange();
        range.selectNodeContents(textbox);
        range.collapse(false);
        range.setEndAfter(o);//
        range.setStartAfter(o);//
        sel.removeAllRanges();
        sel.addRange(range);
    }
});
function browserType () {
        var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串
        var isOpera = false;
        if (userAgent.indexOf('Edge') > -1) {
            return "Edge";
        }
        if (userAgent.indexOf('.NET') > -1) {
            return "IE";
        }
        if (userAgent.indexOf("Opera") > -1 || userAgent.indexOf("OPR") > -1) {
            isOpera = true;
            return "Opera"
        }; //判断是否Opera浏览器
        if (userAgent.indexOf("Firefox") > -1) {
            return "FF";
        } //判断是否Firefox浏览器
        if (userAgent.indexOf("Chrome") > -1) {
            return "Chrome";
        }
        if (userAgent.indexOf("Safari") > -1) {
            return "Safari";
        } //判断是否Safari浏览器
        if (userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1 && !isOpera) {
            return "IE";
        }; //判断是否IE浏览器
}