vue滚动到顶部的问题,类似微信聊天记录?

类似向上滚动加载聊天记录,当我滚动到顶部的时候加载聊条记录,然后滚动条依然停留在最顶部,怎么可以停留在当前的位置

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title></title>
    <style type="text/css">
        * {
            margin: 0;
            padding: 0;
        }
        html, body {
            height: 100vh;
            background-color: #e9f5f8;
        }
        .container {
            width: 200px;
            height: 500px;
            overflow-y: auto;
            background-color: #FFF;
        }
    </style>
    <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
</head>
<body>

    <div id="app">
        <div class="container" @scroll="handleScroll" ref="chatListRef">
            <ul>
                <li v-for="item in msgs"> {{ item }}</li>
            </ul>
        </div>
    </div>

    <script type="module">
        function generateNumbers(start, end) {
          // 确保 start 和 end 是整数
          if (!Number.isInteger(start) || !Number.isInteger(end)) {
            throw new Error('Both start and end must be integers.');
          }

          // 确保 start 小于等于 end
          if (start > end) {
            throw new Error('Start must be less than or equal to end.');
          }

          // 创建一个空数组来存储结果
          const numbers = [];

          // 使用 for 循环生成从 start 到 end 的所有数字
          for (let i = start; i <= end; i++) {
            numbers.push(i);
          }

          return numbers;
        }

        // 示例用法
        const result = generateNumbers(1, 200);
      import { createApp, ref, nextTick } from 'https://lf9-cdn-tos.bytecdntp.com/cdn/expire-1-ms/vue/3.2.31/vue.esm-browser.prod.min.js'

      createApp({
        setup() {
          const msgs = ref(result)
          const chatListRef = ref()

          // 滚动到底部
          const scrollToBottom = async () => {
            const chatListElement = chatListRef.value
            if (chatListElement) {
              chatListElement.scrollTop = chatListElement.scrollHeight
            }
          }

          // 向上滚,当滚到顶部的时候添加新数据
          const handleScroll = (ev) => {
              const target = event.target
              if (target.scrollTop === 0) {
                  msgs.value.unshift(...generateNumbers(201, 400))
                  alert('添加完数据后希望停留在当前数据的位置,而不是最顶部')
              }
          }

          nextTick(() => {
              scrollToBottom()
          })

          return {
            msgs,
            chatListRef,
            handleScroll
          }
        }
      }).mount('#app')
    </script>
</body>
</html>
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