QTextStream out(&file);
qint64 start1 = out.pos();
printf("Start1 is %ld\n",start1);
out<<"123\n" ;
qint64 end1 = out.pos();
printf("end1 is %ld\n",end1);
qint64 start2 = out.pos();
printf("Start2 is %ld\n",start2);
out<<"456\n" ;
qint64 end2 = out.pos();
printf("end2 is %ld\n",end2);
qint64 start3 = out.pos();
printf("Start3 is %ld\n",start3);
out<<"789\n" ;
qint64 end3 = out.pos();
printf("end3 is %ld\n",end3);
我用以上代码，取出来的pos为什么都是一样的呢，start1,2,3和end1，2，3都是一样的值
pos函数应该怎么用，才能自动取出当前的位置呢
