cin>>a1; switch(a1) { case 'a': { cout<<"\t\t\t 请继续选择:"<<endl; cout<<"\t\t\t\t1.按学号查询信息"<<endl; cout<<"\t\t\t\t2.按姓名查询信息"<<endl; int x; cin>>x; switch(x) { case 1:Search1(b,M2);break; case 2:Search2(b,M2);break; default:cout<<"选择错误,请重新选择!"<<endl; } } break; case 'b':Insert(b,M2);break; case 'c': { file.close(); Delete(b); }break; case 'd':Update1(b,M2);break; case 'e':Show(b);break; case 'f': { file.close(); Save(b,M2); cout<<"保存文件成功!"<<endl; fstream file("class.dat",ios_base::in|ios_base::out|ios_base::binary); };break; case 'g':{file.close();break;} default:cout<<"选择错误,请重新选择!"<<endl; } }while(a1!='g'); return 0; }