Element ui 的form表单提交出现如下报错的解决办法

首先，element ui 出现如下报错：

代码：
    <el-form :model="formData" :rules="rules" ref="formData">
                <el-form-item prop="name">
                    <div class="activity-name">活动名称<span class="red">*</span></div>
                    <member-activity-name-input v-model="formData.name"></member-activity-name-input>
                </el-form-item>
                <el-form-item prop="type">
                    <div class="activity-name">使用场景<span class="red">*</span></div>
                    <member-activity-scene-selector v-model="formData.type"></member-activity-scene-selector>
                </el-form-item>
                <el-form-item prop="sendType">
                    <div class="activity-name">触达通路<span class="red">*</span></div>
    <member-activity-channel-selector v-model="formData.sendType" @select-value="channelChanged"
        ></member-activity-channel-selector>
                </el-form-item>
                <div  v-if="formData.sendType === 'SMS'">
                     <el-form-item  prop="requireType">
                    <div class="activity-name">短信类型<span class="red">*</span></div>
                     <member-activity-smstype-selector v-model="formData.requireType"></member-activity-smstype-selector>
                </el-form-item>
                </div>
                <el-form-item prop="remarks">
                    <div class="activity-name">备注<span class="red">*</span></div>
                      <el-input type="textarea" placeholder="输入备注信息" v-model="formData.remarks"
                    class="comments"show-word-limit maxlength="200"></el-input>
                </el-form-item>
                <el-form-item >
                 <div class="activity-name mb15">状态<span class="red">*</span></div>
                    <el-radio-group v-model="formData.isDel">
                        <el-radio label="1">已激活</el-radio>
                        <el-radio label="2">未激活</el-radio>
                    </el-radio-group>
                </el-form-item>
            </el-form>
            <span slot="footer" class="dialog-footer">
                <el-button type="primary" @click="handleClose('formData')" class="next">下一步</el-button>
            </span>

   //js方法
handleClose(formName) {
            // this.rules

           this.$refs[formName].validate((valid) => {
          if (valid) {
            alert('submit!');
             this.dialogVisible= false;
             this.targetVisible=true;
          } else {
            console.log('error submit!!');
            return false;
          }
        });

错误代码：

正确代码：

  <span slot="footer" class="dialog-footer">
                <el-button type="primary" @click="handleClose('formData')" class="next">下一步</el-button>
            </span>

错误原因：少加了一个‘’