fix：未选中客户提交按钮禁用

src/modules/system/customergroup/components/AddCustomer.vue

@@ -7,7 +7,9 @@
         </template>
         <template #footer>
           <el-button @click="$emit('update:visible', false)" style="margin-left: 20px">取消</el-button>
-          <el-button type="primary" @click="submit" :disabled="btnDisabled">提交</el-button>
+          <el-button type="primary" @click="submit" :disabled="btnDisabled || multipleSelection.length === 0"
+            >提交</el-button
+          >
         </template>
       </app-list>
     </app-card>