修复多栏题卡学生准考证未知获取有误问题

src/modules/card/components/SavePage.vue

@@ -178,9 +178,13 @@ export default {
         });
       } else {
         // barcode
+        const stdnoDom =
+          element.columnNumber <= 2
+            ? dom.querySelector(".head-stdno").parentNode
+            : dom.querySelector(".head-stdno");
         barcode.push({
           field: "examNumber",
-          area: this.getOffsetInfo(dom.querySelector(".head-stdno").parentNode)
+          area: this.getOffsetInfo(stdnoDom)
         });
       }
       // 缺考涂填