element-ui el-upload实现上传文件及简单的上传文件格式验证功能

 <el-fORM-item label="使用说明" class="uploadMain" prop="instruction">
              <el-input
                class="uploadInput"
                v-model="productVO.instruction"
                style="width: 75%"
                placeholder="请上传pdf格式的使用说明文件"
                :disabled="true"
              >
                <el-upload
                  slot="append"
                  class="uploadbox"
                  ref="upload"
                  name="file"
                  accept=".pdf"    //接受上传文件的格式，此处会默认打开上传时筛选.pdf格式
                  :show-file-list="false"
                  :multiple="false"  //如果想要一次选择多个文件 mulitiple为true
                  action="upload"
                  :on-change="onChange"
                  :auto-upload="false"  //自动上传，如果此处为true 选择完文件就直接上传了
                >
                  <!-- class="uploadbtn" -->
                  <el-button class="uploadbtn"></el-button>
                </el-upload>
              </el-input>
            </el-form-item>

onChange(file) {
            // 校验格式
            if (['application/pdf'].indexOf(file.raw.type) == -1) {
                this.$message.error('请上传正确的pdf格式');
                return false;
            }
            this.productVO.instruction = file.name;
            this.productVO.instructionFile = file.raw; //上传文件时需要用到二进制，所以这里文件取值为file.raw
        },

submit(){
     const formData = new FormData();
     formData.append('instruction', this.productVO.instruction);
     formData.append('instructionFile',this.productVO.instructionFile);
    
 
     //调用接口
     this.$post('/product/create',formData,{
         baseURL:'/',
         header:{isloading: true,'Content-Type': 'multipart/form-data'}).then()
}

<el-form-item label="数据" class="uploadMain" prop="entity">
              <el-input
                class="uploadInput"
                v-model="productVO.entity"
                style="width: 75%"
                placeholder="请上传完整的tif/tiff/shp格式的数据文件"
                :disabled="true"
              >
                <el-upload
                  slot="append"
                  class="uploadbox"
                  ref="upload"
                  name="file"
                  accept=".tif,.tiff,.shp,.dbf,.prj,.sbn,.sbx,.shx"
                  :show-file-list="false"
                  multiple
                  :file-list="this.productVO.fileList"
                  action="upload"
                  :on-change="onChange"
                  :auto-upload="false"
                >
                  <!-- class="uploadbtn" -->
                  <el-button class="uploadbtn"></el-button>
                </el-upload>
              </el-input>
              <div style="color: #ffc230">此处是文本说明</div>
            </el-form-item>

onChange(file,fileList) {
            // 校验格式
            if (['image/tiff', ''].indexOf(file4.raw.type) == -1) {
                this.$message.error('请上传正确的tif/tiff/shp格式');
                return false;
            }else{
                this.productVO.fileList=fileList
                console.log(this.productVO.fileList)
                var listName=[]
                this.productVO.fileList.forEach(function(e){listName.push(e.name)})
                var listFileRaw=[]
                this.productVO.fileList.forEach(function(e){listFileRaw.push(e.raw)})
                this.productVO.entity = listName; //文本框显示所有的文件名
                this.productVO.entityFile = listFileRaw;
            }
           
        },

 this.productVO.entityFile.forEach(element => {
                        formData.append('entityFile', element)
                      })