columns default value

ruoyi-ui/src/components/RightToolbar/index.vue

@@ -7,7 +7,7 @@
       <el-tooltip class="item" effect="dark" content="刷新" placement="top">
         <el-button size="mini" circle icon="el-icon-refresh" @click="refresh()" />
       </el-tooltip>
-      <el-tooltip class="item" effect="dark" content="显隐列" placement="top" v-if="columns">
+      <el-tooltip class="item" effect="dark" content="显隐列" placement="top" v-if="Object.keys(columns).length > 0">
         <el-button size="mini" circle icon="el-icon-menu" @click="showColumn()" v-if="showColumnsType == 'transfer'"/>
         <el-dropdown trigger="click" :hide-on-click="false" style="padding-left: 12px" v-if="showColumnsType == 'checkbox'">
           <el-button size="mini" circle icon="el-icon-menu" />
@@ -58,7 +58,8 @@ export default {
     },
     /* 显隐列信息（数组格式、对象格式） */
     columns: {
-      type: [Array, Object]
+      type: [Array, Object],
+      default: () => ({})
     },
     /* 是否显示检索图标 */
     search: {