vant slot插槽

<van-col span="12">
                        <van-field label="载重量：" placeholder="保留2位小数" name="dweight" :value="dweight"
                                   v-on:touchend.native.stop="weightkeyPos"></van-field>
                    </van-col>

<van-number-keyboard
                        v-model="weight"
                        :show="weightshow"
                        title="输入载重量"
                        extra-key="."
                        close-button-text="完成"
                        v-on:blur="weightval"
                        v-on:delete="jponDelete"
                >
                    <template v-slot:title-left>
                        <div v-on:click="cancelNum" class="paddlr16 maincol1">取消</div>
                    </template>
                </van-number-keyboard>

完成按钮可以检查输入验证，取消按钮只是收起键盘