[Vue] 消失的字段?

Question

环境

• element-ui: 2.4.6
• vue: 2.5.17

描述

1. 填写表单

2. 上传图片, 返回url, 绑定到courseInfo对象

<!-- 课程封面 TODO -->

  <el-form-item label="课程封面">
    <el-upload
      :show-file-list="false"
      :on-success="handleAvatarSuccess"
      :before-upload="beforeAvatarUpload"
      :action="BASE_API+'/eduoss/fileoss/uploadAvater'"
      class="avatar-uploader"
    >
      <img :src="courseInfo.cover" />
    </el-upload>
  </el-form-item>
  
// courseInfo对象
courseInfo: {
    title: "",
    subjectId: "",
    subjectParentId: "",
    teacherId: "",
    lessonNum: 0,
    description: "",
    cover: "",
    price: 0,
  }
  
handleAvatarSuccess(res, file) {
  //图片上传成功
  console.log(res); // 上传响应
  console.log(URL.createObjectURL(file.raw)); // base64编码
  this.courseInfo.cover = res.data.url;
}
```

1. 提交表单

问题: 发送post请求, 发现request参使中 courseInfo.cover 字段没有值(没有cover字段), 用插值表达式也不显示

// Request Payload
description: "<p>...</p>"
lessonNum: 11
price: 10
subjectId: "1178214681210843137"
subjectParentId: "1178214681181483010"
teacherId: "1"
title: "NodeJs大师课"

下面是我的完整代码

<!--  -->
<template>
  <div>
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="marginbottom: 40px;">
      <el-step title="填写课程基本信息" />
      <el-step title="创建课程大纲" />
      <el-step title="发布课程" />
    </el-steps>
    <br />

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视"></el-input>
      </el-form-item>

      <el-form-item label="课程讲师">
        <el-select v-model="courseInfo.teacherId" placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"
          />
        </el-select>
      </el-form-item>

      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          @change="subjectLevelOneChanged"
          placeholder="一级分类"
        >
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number
          :min="0"
          v-model="courseInfo.lessonNum"
          controls-position="right"
          placehol="单位分钟"
        ></el-input-number>
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description" />
      </el-form-item>
      <!-- 课程封面 TODO -->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss/uploadAvater'"
          class="avatar-uploader"
        >
          <img :src="courseInfo.cover" />
        </el-upload>
      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number
          :min="0"
          v-model="courseInfo.price"
          controls-position="right"
          placehol="保留两位小数"
        ></el-input-number>
      </el-form-item>
      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
//这里可以导入其他文件（比如：组件，工具js，第三方插件js，json文件，图片文件等等）
//例如：import 《组件名称》 from '《组件路径》';
import course from "@/api/edu/course";
import { getSubjectList } from "@/api/edu/subject";
import Tinymce from "@/components/Tinymce";

export default {
  //import引入的组件需要注入到对象中才能使用
  components: { Tinymce },
  data() {
    //这里存放数据
    return {
      saveBtnDisabled: false, // 保存按钮是否禁用
      teacherList: [], // 讲师列表
      subjectOneList: [], // 一级分类列表
      subjectTwoList: [], // 二级分类列表
      courseInfo: {
        title: "",
        subjectId: "",
        subjectParentId: "",
        teacherId: "",
        lessonNum: 0,
        description: "",
        cover: "",
        price: 0,
      },
      courseId: "",
      BASE_API: process.env.BASE_API, // 接口API地址
    };
  },
  //计算属性
  computed: {},
  //监控data中的数据变化
  watch: {},
  //方法集合
  methods: {
    getInfo() {
      course.getCourseInfo(this.courseId).then((res) => {
        this.courseInfo = res.data.courseInfo;
        // 获取分类列表
        getSubjectList().then((res) => {
          this.subjectOneList = res.data.list;

          for (let i = 0; i < this.subjectOneList.length; i++) {
            var oneSubject = this.subjectOneList[i];

            if (this.courseInfo.subjectParentId === oneSubject.id) {
              this.subjectTwoList = oneSubject.children;
            }
          }
        });
        this.getTeacherList();
      });
    },
    addCourse() {
      course.addCourseInfo(this.courseInfo).then((res) => {
        this.$message({
          type: "success",
          message: "保存课程信息成功",
        });
        console.log("next");
        // 跳转到第二步, 传递课程id
        this.$router.push({ path: "/course/chapter/" + res.data.courseId });
      });
    },
    updateCourse() {
      course.updateCourseInfo(this.courseInfo).then((res) => {
        this.$message({
          type: "success",
          message: "修改课程信息成功",
        });
        // 跳转到第二步, 传递课程id
        this.$router.push({ path: "/course/chapter/" + this.courseId });
      });
    },
    saveOrUpdate() {
      if (!this.courseInfo.id) {
        this.addCourse();
      } else {
        this.updateCourse();
      }
    },
    getTeacherList() {
      course.getListTeacher().then((res) => {
        console.log(res);
        this.teacherList = res.data.items;
      });
    },
    getOneSubject() {
      getSubjectList().then((res) => {
        this.subjectOneList = res.data.list;
      });
    },
    subjectLevelOneChanged(value) {
      // 点击某个一级分类后显示对应的二级分类
      console.log(value);
      for (let i = 0; i < this.subjectOneList.length; i++) {
        // 每个一级分类
        var oneSubject = this.subjectOneList[i];
        // 判断所有所有一级分类id 和 被点击的分类id一样
        if (oneSubject.id === value) {
          this.subjectTwoList = oneSubject.children;
          this.courseInfo.subjectId = "";
        }
      }
    },
    handleAvatarSuccess(res, file) {
      //图片上传成功
      console.log(res); // 上传响应
      console.log(URL.createObjectURL(file.raw)); // base64编码
      this.courseInfo.cover = res.data.url;
    },
    beforeAvatarUpload(file) {
      //图片上传之前
      const isJPG = file.type === "image/jpeg";
      const isPNG = file.type === "image/png";
      const isLt2M = file.size / 1024 / 1024 < 2;
      if (!isJPG && !isPNG) {
        this.$message.error("上传头像图片只能是 JPG/PNG 格式!");
      }
      if (!isLt2M) {
        this.$message.error("上传头像图片大小不能超过 2MB!");
      }
      return isJPG && isLt2M;
    },
  },
  //生命周期 - 创建完成（可以访问当前this实例）
  created() {
    console.log("init data");

    if (this.$route.params && this.$route.params.id) {
      this.courseId = this.$route.params.id;
      this.getInfo();
    } else {
      this.courseInfo = {};
      this.getTeacherList();
      this.getOneSubject();
    }
  },
  //生命周期 - 挂载完成（可以访问DOM元素）
  mounted() {},
  beforeCreate() {}, //生命周期 - 创建之前
  beforeMount() {}, //生命周期 - 挂载之前
  beforeUpdate() {}, //生命周期 - 更新之前
  updated() {}, //生命周期 - 更新之后
  beforeDestroy() {}, //生命周期 - 销毁之前
  destroyed() {}, //生命周期 - 销毁完成
  activated() {}, //如果页面有keep-alive缓存功能，这个函数会触发
};
</script>
<style scoped>
/*@import url(); 引入公共css类*/
.tinymce-container {
  line-height: 29px;
}
</style>

求指点, 谢谢!

Answer 1

找问题一

是不是你这里没有对应cover值

找问题二

在提交前，打印this.courseInfo.cover是否有值