fix: 兼容空题卡数据

src/views/base/track-export/useDraw.ts

@@ -225,9 +225,10 @@ export default function useDraw(winId: number) {
 
     // 获取题卡数据
     const cardRes = await getSingleStudentCardData(studentId);
-    const cardContent = cardRes.content
-      ? (JSON.parse(cardRes.content) as CardContentType)
-      : { pages: [] };
+    const cardContent =
+      cardRes && cardRes.content
+        ? (JSON.parse(cardRes.content) as CardContentType)
+        : { pages: [] };
     cardData = cardContent.pages;
   }