fprintf不写入文件

Question

有没有人看到，为什么fprintf在printf工作正常时不写入文件？

 FILE* database;
  database = fopen("database.txt", "a+");



   for (x=-200; x<200; x=x+10)
    {     
TH1F *hist_Deg = new TH1F("h1", "title", 250, -0.5, 249.5);

 for (j=5000; j<5010; j++)

 {
      sprintf(filename,"electronsrough/105.000000MeV/x%d/y0/process%d.txt", x,j);

      FILE* pfile =fopen(filename,"r");

      while(!feof(pfile))
        {
          fscanf(pfile, "%lf /n", &p);

          hist_Deg->Fill(p);
          } 
fclose(pfile);

 }

 meana = hist_Deg->GetMean();


 f->SetPoint(i, x, meana);
 i=i+1;


 fprintf(database, "%f\n", meana);
 printf("%f\n", meana);

 delete hist_Deg;

} 

printf将meana输出到comman行，但是

文件“database.txt”已创建，但仍为空。

Answer 1

刷新和关闭数据库文件应该可以完成这项工作。

fprintf(database, "%f\n", meana);
fflush(database);
fclose(database);