fix

examcloud-core-oe-student-service/src/main/java/cn/com/qmth/examcloud/core/oe/student/service/impl/ExamControlServiceImpl.java

@@ -1744,7 +1744,13 @@ public class ExamControlServiceImpl implements ExamControlService {
                 examSessionInfo.getExamId(), examSessionInfo.getExamStudentId()));
 
         // 返回考试剩余时间
-        long leftTime = examSessionInfo.getExamDuration() - (examingHeartbeat.getCost() * 1000);
+        long leftTime =0;
+        if(examSessionInfo.getTimingEnd()) {//定点收卷
+        	Date now=new Date();
+        	leftTime=examSessionInfo.getFixedSubmitTime().getTime()-now.getTime();
+        }else {
+        	leftTime=examSessionInfo.getExamDuration() - (examingHeartbeat.getCost() * 1000);
+        }
         return leftTime < 0 ? 0 : leftTime;
     }