element-ul popup processing problems within the assembly close

  <el-dialog
            custom-class="rental-pop"
            :close-on-click-modal="false"
            :append-to-body="true"
            title="租赁详情"
            width="30%"
            :visible.sync="dialogShow"
            :before-close='close'
            >
            <div class="content rental-box">
             
            </div>
            <span slot="footer" class="dialog-footer">
                <el-button type="primary" @click="close">取 消</el-button>
            </span>
   </el-dialog>

　　

: Before-close = 'starting method of the external component to the attribute' pop-up box assembly disposed within close problems