Javascript 在底部滚动

我正在用angular js制作一个聊天应用程序，我已经在聊天区添加了滚动条。 代码如下：

<div class="chat active-chat" id="scrollme" >
   <div class="scroll">
      <div ng-repeat="c in activeConversations track by c.time| orderBy:'time':false" >
         <div class="bubble" ng-class="c.type" >
            {{c.message}} <br/>
            <a style="color: blue;" ng-click="openFile(c.uploadedFile.fileContentType, c.uploadedFile.file)" ng-if="c.uploadedFile.file" target="_blank">{{c.uploadedFile.fileName}}
            </a> &nbsp;&nbsp;&nbsp;&nbsp;
            <span class="user_message">{{c.time | date:'yyyy-MM-dd HH:mm:ss'}}</span>
         </div>
      </div>
   </div>
</div>

现在我想在默认情况下将滚动条保持在底部，每当消息到达时，滚动条都应该向上滚动

---

提前感谢

将其保留在底部：

您只需将scrollTop设置为元素的高度：

更改以下元素：

有关此功能，请参见小提琴：

对于更新元素scrollTop值的聊天：

假设不断更新的聊天对象是JSON表示，您只需查看JSON字符串值：

$scope.$watch('activeConversations', function(newValue, oldValue) {
  var ele = document.getElementById('scrollme');
  var curScrollTop = ele.scrollTop;
  ele.scrollTop = curScrollTop - 16; //Go up 16 pixels, but you can change this as you need
});

---

var textarea=document.getElementById（'textarea_id'）；textarea.scrollTop=textarea.scrollHeight；

var ele = document.getElementById('scrollme');
var innerEle = document.getElementById('innerScroll') //add this ID to your scroll class element. Or whatever name you want to
var height = innerEle.offsetHeight;
ele.scrollTop = height;

$scope.$watch('activeConversations', function(newValue, oldValue) {
  var ele = document.getElementById('scrollme');
  var curScrollTop = ele.scrollTop;
  ele.scrollTop = curScrollTop - 16; //Go up 16 pixels, but you can change this as you need
});