一个程序的问题

Question

DateTime kqlssj1;
                if (rowkqls.Issj1Null())
                {
                    rowkqls.ssbqk = "未考勤";
                }
                else 
                {
                    //DateTime 
                        kqlssj1 = rowkqls.sj1;
                }
  if (ss && rowkqls.Issj1Null())
                {
                    TimeSpan t1 = kqlssj1.TimeOfDay.Subtract(Sjsj1.TimeOfDay);
编译后出错，说
 TimeSpan t1 = kqlssj1.TimeOfDay.Subtract(Sjsj1.TimeOfDay);
中的kqlssj1未赋值，这个是怎么回事啊

Answer 1

将DateTime kqlssj1;改成
DateTime kqlssj1 = DateTime.Now;