可编辑的div，如何在输入的文字、图片或文件后面获取光标？

// 获取光标
set_focus(){
    let el=document.getElementById('uploadArea');
    el.focus();
    if($.support.msie){
        var range = document.selection.createRange();
        this.last = range;
        range.moveToElementText(el);
        range.select();
        document.selection.empty(); //取消选中
    }else {
        var range = document.createRange();
        range.selectNodeContents(el);
        range.collapse(false);
        var sel = window.getSelection();
        sel.removeAllRanges();
        sel.addRange(range);
    }
}