el-date-picker的时间选择不回显

遇到选择了时间但是时间组件却没有变化
代码：

<el-form :inline="true" ref="uploadForm1"
                         :model="uploadForm1">
                    <el-form-item label="日期:" prop="reportDate">
                        <el-date-picker
                                :type="fileType"
                                v-model="uploadForm1.reportDate"
                                value-format="yyyy-M-dd"
                                placeholder="请选择日期">
                        </el-date-picker>
                    </el-form-item>
                    <el-form-item label="区域名称:" prop="area_ID">
                        <el-select v-model="uploadForm1.area_ID" placeholder="请选择">
                            <el-option v-for="item in areaList" :value="item.area_ID" :label="item.area_Name"></el-option>
                        </el-select>
                    </el-form-item>
                    <el-form-item label-width="0">
<!--                        <el-button-->
<!--                                type="primary"-->
<!--                                icon="el-icon-search"-->
<!--                                native-type="submit"-->
<!--                                @click="handleUpload('uploadForm')"-->
<!--                        >上传-->
<!--                        </el-button>-->
                        <el-button type="primary" @click="uploadDateInfo('uploadForm1')" icon="el-icon-search" style="margin-left: 30px">查询</el-button>
                    </el-form-item>
                </el-form>

ts:

解决办法：

        uploadForm1: any = {
            reportDate: "",
            area_ID: 1
        };

给对象里面加入属性，他就能找到属性名就能够回显示