器件选型页面为buy插件做if判断（什么情况下显示—，什么情况下显示购物车和立即购买）

components/product/ComponentGoods.vue

@@ -86,10 +86,12 @@
           </div>
         </td>
         <td>
-          <div v-if="!compGoods.reserve">
+          <div v-show="!compGoods.reserve">
             <span>—</span>
           </div>
-          <buy :item="compGoods"></buy>
+          <div v-if="compGoods.reserve > 0">
+            <buy :item="compGoods"></buy>
+          </div>
         </td>
       </tr>
       <tr v-if="componentGoods.totalElements == 0">