1 //**************************************************************************************************************  2 //作者：  3 //日期：2018/3/19  4 //学号：  5 //题号：5-5  6 //题目：编写一个程序，实现以下功能：  7   8 //      1)输入一系列的学生数据（包括学生的学号、姓名和成绩等基本信息），将学生信息写入二进制文件student.dat中。  9  10 //      2)从student.dat文件中读出这些数据并显示出来。 11  12 //      3)在student.dat文件中按姓名进行查询，如输入“李”，则将所有姓“李”的学生的   数据显示出来。 13  14 //      4)可对指定学生的数据进行修改。 15  16 //      5)可以删除指定的学生数据。 17  18 //************************************************************************************************************** 19  20  21  22 #include
     
       23 #include
      
        24 #include
       
         25 #include
        
          26 using namespace std; 27 struct Std 28 { 29     char name[20]; 30     char id[20]; 31     char score[5]; 32 }; 33 void getinfo(char filename[]); 34 void showinfo(char filename[]); 35 void searchinfo(char filename[]); 36 void editinfo(char filename[]); 37 void deleteinfo(char filename[]); 38  39 int main() 40 { 41     fstream student; 42     char choice; 43     char filename[20]; 44     cout << "Please type in the filename:"; 45     cin.getline(filename,20); 46     cout << endl; 47     while(true) 48     { 49         cout << "Please type down the manipulation code:\nA.Input information\tB.Show information\tC.Search\tD.Edit\tE.Delete\tF.Exit\n"; 50         cout << endl; 51         cin >> choice; 52         switch(choice) 53         { 54             case'A': 55             case'a':getinfo(filename);break; 56             case'B': 57             case'b':showinfo(filename);break; 58             case'C': 59             case'c':searchinfo(filename);break; 60             case'D': 61             case'd':editinfo(filename);break; 62             case'E': 63             case'e':deleteinfo(filename);break; 64             case'F': 65             case'f':exit(0); 66         } 67         cout << endl; 68     } 69     return 0; 70 } 71  72 void getinfo(char filename[]) 73 { 74     fstream student; 75     student.open(filename,ios::out|ios::binary); 76     if(!student) 77     { 78         cout << "Error!"; 79         exit(0); 80     } 81     int count; 82     cout << "How many student's information would you like to input?"; 83     cin >> count; 84     Std *Student; 85     Student = new struct Std[count]; 86     for(int i=0;i
         
          > Student[i].score; 95         student.write((char*)&Student[i],sizeof(Student[i])); 96     } 97     cout << "Done."; 98     delete[]Student; 99     student.close();100 }101 102 void showinfo(char filename[])103 {104     fstream student;105     student.open(filename,ios::in|ios::binary);106     if(!student)107     {108         cout << "Error!";109         exit(0);110     }111     Std Student;112     student.read((char*)&Student,sizeof(Student));113     while(!student.eof())114     {115         cout << "name:";116         cout << Student.name <
          
           > Name;140 long position = student.tellg();141 cout << "position:"<
           
            <
            
             > editid;201 student.seekg(0L,ios::beg);202 student.seekg(sizeof(Student.name),ios::beg);203 student.seekp(0L,ios::beg);204 student.read((char*)&Student.id,sizeof(Student.id));205 while(!student.eof())206 {207 if(strcmp(editid,Student.id)==0)208 {209 student.seekg(-sizeof(Student.id)-sizeof(Student.name),ios::cur);210 student.read((char*)&Student,sizeof(Student));211 cout << "The information of the student:"<
             
              > Student.name;218 cout << "id:";219 cin >> Student.id;220 cout << "score:";221 cin >> Student.score;222 student.write((char*)&Student,sizeof(Student));223 break;224 }225 student.seekg(sizeof(Student),ios::cur);226 student.seekp(sizeof(Student),ios::cur);227 }228 cout << "Done.";229 student.close();230 }231 232 void deleteinfo(char filename[])233 {234 fstream student;235 Std Student;236 student.open(filename,ios::in|ios::out|ios::binary);237 if(!student)238 {239 cout << "Error!";240 exit(0);241 }242 char deleid[20];243 cout << "Please input the id of the student whose information needs to be erased:";244 cin >> deleid;245 student.seekg(0L,ios::beg);246 student.seekg(sizeof(Student.name),ios::beg);247 student.seekp(0L,ios::beg);248 student.read((char*)&Student.id,sizeof(Student.id));249 while(!student.eof())250 {251 if(strcmp(deleid,Student.id)==0)252 {253 student.seekg(-sizeof(Student.id)-sizeof(Student.name),ios::cur);254 student.read((char*)&Student,sizeof(Student));255 cout << "The information of the student:"<
              
               > code;262 if(code == 'd')263 {264 strcpy(Student.name,0);265 strcpy(Student.id,0);266 strcpy(Student.score,0);267 }268 student.write((char*)&Student,sizeof(Student));269 break;270 }271 student.seekg(sizeof(Student),ios::cur);272 student.seekp(sizeof(Student),ios::cur);273 }274 cout << "Done.";275 student.close();276 }