如何使滚动条始终位于聊天底部

Question

我有一个聊天框，如果有新消息要来，滚动条也会自动滚动到底部，因此我必须始终将滚动条保持在聊天底部。 我使用的滚动聊天框的代码也只有一半，当新消息弹出时它不会滚动到底部。

$('#chat_history_'+to_user_id).stop().animate({ scrollTop: $('#chat_history_'+to_user_id)[0].scrollHeight}, 1000);

Answer 1

这是你的解决方案

  window.alert = function(){}; var defaultCSS = document.getElementById('bootstrap-css'); function changeCSS(css){ if(css) $('head > link').filter(':first').replaceWith('<link rel="stylesheet" href="'+ css +'" type="text/css" />'); else $('head > link').filter(':first').replaceWith(defaultCSS); } $("#submit").click(function() { var data = $("#btn-input").val(); //console.log(data); $('chat_log').append('<div class="row msg_container base_sent"><div class="col-md-10 col-xs-10"><div class="messages msg_receive"><p>'+data+'</p></div></div></div><div class="row msg_container base_receive"><div class="col-md-10 col-xs-10"><div class="messages msg_receive"><p>'+data+'</p></div></div></div>'); clearInput(); $(".msg_container_base").stop().animate({ scrollTop: $(".msg_container_base")[0].scrollHeight}, 1000); }); function clearInput() { $("#myForm :input").each(function() { $(this).val(''); //hide form values }); } $("#myForm").submit(function() { return false; //to prevent redirection to save.php }); 

 .msg_container_base{ background: #e5e5e5; margin: 0; padding: 0 10px 10px; max-height:80vh; overflow-x:hidden; } .top-bar { background: #666; color: white; padding: 10px; position: relative; overflow: hidden; } .msg_receive{ padding-left:0; margin-left:0; } .msg_sent{ padding-bottom:20px !important; margin-right:0; } .messages { background: white; padding: 10px; border-radius: 2px; box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2); max-width:100%; } .messages > p { font-size: 13px; margin: 0 0 0.2rem 0; } .messages > time { font-size: 11px; color: #ccc; } .msg_container { padding: 10px; overflow: hidden; display: flex; } img { display: block; width: 100%; } .avatar { position: relative; } .base_receive > .avatar:after { content: ""; position: absolute; top: 0; right: 0; width: 0; height: 0; border: 5px solid #FFF; border-left-color: rgba(0, 0, 0, 0); border-bottom-color: rgba(0, 0, 0, 0); } .base_sent { justify-content: flex-end; align-items: flex-end; } .base_sent > .avatar:after { content: ""; position: absolute; bottom: 0; left: 0; width: 0; height: 0; border: 5px solid white; border-right-color: transparent; border-top-color: transparent; box-shadow: 1px 1px 2px rgba(black, 0.2); // not quite perfect but close } .msg_sent > time{ float: right; } .msg_container_base::-webkit-scrollbar-track { -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3); background-color: #F5F5F5; } .msg_container_base::-webkit-scrollbar { width: 12px; background-color: #F5F5F5; } .msg_container_base::-webkit-scrollbar-thumb { -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,.3); background-color: #555; } .btn-group.dropup{ position:fixed; left:0px; bottom:0; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="panel panel-primary" style="border:0px"> <div class="panel-heading top-bar"> <div class="col-md-8 col-xs-8"> <h3 class="panel-title"><span class="glyphicon glyphicon-comment" style="margin-right:6px;"></span>College Enquiry Chat</h3> </div> </div> <div class="panel-body msg_container_base"> <div class="row msg_container base_sent"> <div class="col-md-10 col-xs-10"> <div class="messages msg_sent"> <p>that mongodb thing looks good, huh? tiny master db, and huge document store</p> </div> </div> </div> <div class="row msg_container base_receive"> <div class="col-md-10 col-xs-10"> <div class="messages msg_receive"> <p>that mongodb thing looks good, huh? tiny master db, and huge document store</p> </div> </div> </div> <chat_log> . </chat_log> </div> <!--CHAT USER BOX--> <div class="panel-footer"> <div class="input-group" id="myForm"> <input id="btn-input" type="text" class="form-control input-sm chat_input" placeholder="Write your message here..."> <span class="input-group-btn"> <button class="btn btn-primary btn-sm" id="submit" type="submit">Send</button> </span> </form> </div> </div> </div> </div> </div> </div> 

见代码链接