我一次通过菜单点击用户列表请求是正常的

但是按F5刷新之后，页面就直接丢失了，请求的参数也不对，后台也报page没有传值

<template>
  <div class="user-list-box">
    <div class="user-search-pat">
      <el-form :inline="true">
        <el-form-item label="用户名" size="medium">
          <el-input v-model="search.username" placeholder="请输入用户名"></el-input>
        </el-form-item>
        <el-form-item label="邮箱">
          <el-input v-model="search.email" placeholder="请输入邮箱地址"></el-input>
        </el-form-item>
        <el-form-item>
          <el-button type="primary" @click="doSearch">搜索</el-button>
        </el-form-item>
      </el-form>
    </div>
    <!--显示内容-->
    <div class="list-box">
      <el-table
          :data="userList"
          style="width: 100%">
        <el-table-column
            fixed
            prop="id"
            label="ID"
            width="200">
        </el-table-column>
        <el-table-column
            prop="username"
            label="用户名"
            width="120">
        </el-table-column>
        <el-table-column
            prop="email"
            label="邮箱"
            width="120">
        </el-table-column>
        <el-table-column
            prop="sign"
            label="签名"
            width="120">
        </el-table-column>
        <el-table-column
            label="头像"
            width="200">
          <template slot-scope="scope">
            <el-avatar size="medium" :src="scope.row.avatar"></el-avatar>
          </template>
        </el-table-column>
        <el-table-column
            label="状态"
            width="120">
          <template slot-scope="scope">
            <div v-if="scope.row.state==='0'">
              <el-tag type="danger" size="mini">不可用</el-tag>
            </div>
            <div v-if="scope.row.state==='1'">
              <el-tag type="success" size="mini">正 常</el-tag>
            </div>
          </template>
        </el-table-column>
        <el-table-column
            label="创建日期"
            width="180">
          <template slot-scope="scope">
            <span v-text="formatDate(scope.row.createTime)"></span>
          </template>
        </el-table-column>
        <el-table-column
            label="更新日期">
          <template slot-scope="scope">
            <span v-text="formatDate(scope.row.updateTime)"></span>
          </template>
        </el-table-column>
        <el-table-column
            fixed="right"
            label="操作"
            width="200">
          <template slot-scope="scope">
            <el-button @click="resetPassword(scope.row)" type="primary" size="mini">重置密码</el-button>
            &nbsp;
            <el-popconfirm
                :hideIcon="true"
                @onConfirm="deleteItem(scope.row)"
                cancelButtonType="Text"
                confirmButtonType="Text"
                title="是否确定删除">
              <el-button slot="reference" type="danger" size="mini">删除</el-button>
            </el-popconfirm>
          </template>
        </el-table-column>
      </el-table>
    </div>
    <div class="page-navigation-box">
      <el-pagination
          class="user-list-page-navigation-bar clearfix"
          background
          layout="prev, pager, next"
          @current-change="onPageChange"
          :current-page="pageNavigation.currentPage"
          :page-size="pageNavigation.pageSize"
          :total="pageNavigation.totalCount">
      </el-pagination>
    </div>
  </div>
</template>

<script>
import * as dateUtils from '../../utils/date'
export default {
  name: "list",
  data() {
    return {
      search:{
        username: '',
        email: ''
      },
      userList:[],
      pageNavigation: {
        currentPage: 1,
        totalCount: 0,
        pageSize: 10
      }
    }
  },
  methods: {
    formatDate(dateStr) {
      let date = new Date(dateStr)
      return dateUtils.formatDate(date, 'yyyy-MM-dd hh:mm:ss')
    },
    listUsers() {
      // http://localhost:8081/user/list?page=1&size=5
      this.axios.get('/user/list?page='+ this.pageNavigation.currentPage+'&size='+ this.pageNavigation.pageSize).then(result =>{
        this.handleUserListResult(result)
      })
    },
    handleUserListResult(result){
      if (result.data.code === 200){
        this.userList = result.data.data.list
        this.pageNavigation.currentPage = result.data.data.pageNum;
        this.pageNavigation.totalCount = result.data.data.total;
        this.pageNavigation.pageSize = result.data.data.pageSize;
      }else {
        this.$message.error(result.data.message)
      }
    },
    resetPassword(){

    },
    deleteItem(){

    },
    doSearch(){
      this.$message('功能开发中');
    },
    onPageChange(page){
      this.pageNavigation.currentPage = page;
      this.listUsers()
    }
  },
  mounted() {
    this.listUsers()
  }
}
</script>

<style scoped>
  .clearfix{
    overflow: auto;
    zoom: 1;
  }
  .user-list-page-navigation-bar{
    float: right;
    margin-right: 40px;
  }
  .list-box{
    margin-bottom: 10px;
  }
</style>