导出优化

front-vue/src/views/service/cost/userCostManage.vue

@@ -78,6 +78,7 @@
           size="mini"
           @click="handleExport"
           v-hasPermi="['service:cost:export']"
+          :disabled="total == 0"
         >导出</el-button>
       </el-col>
     </el-row>