文件IO操作学习中出错的地方

问题1：

file1:

     1  #include<iostream>
     2  #include<fstream>
     3
     4  using namespace std;
     5  class Sprite
     6  {
     7  public:
     8        Sprite(){};
     9        Sprite(string profession,string weapon):profession(profession),weapon(weapon){};
    10        void showSprite();
    11  private:
    12        string profession;
    13        string weapon;
    14        static int count;
    15  };
    16  int Sprite::count=0;
    17  void Sprite:: showSprite()
    18  {
    19  ++count;
    20  cout<<"jingling:"<<count<<"zhiye:"<<profession<<"wuqi:"<<weapon<<endl;
    21  }
    22
    23
    24  int main()
    25  {
    26   Sprite sprites[3]={Sprite("fashi","mozhang"),Sprite("zhanshi","tulongbaoda"),Sprite("daoshi","yitianjian")};
    27   ofstream file("file.data",ios::ate|ios::binary);
    28   if (!file)
    29   {
    30    cout<<"can't open the file"<<endl;
    31    return 1;
    32   }
    33   for (int i=0;i<3;i++)
    34   {
    35    file.write((char*)&sprites[i],sizeof(sprites[i]));
    36   }
    37  file.close();
    38
    39  return 0;
    40
    41  }

 

File2.cpp

     1  #include<iostream>
     2  #include<fstream>
     3  using namespace std;
     4  class Sprite
     5  {
     6          public:
     7                  Sprite(){};
     8                  Sprite(string profession,string weapon):profession(profession),weapon(weapon){};
     9                  void showSprite();
    10          private:
    11                  string profession;
    12                  string weapon;
    13                  static int count;
    14
    15  };
    16  int Sprite::count=0;
    17  void Sprite::showSprite()
    18  {
    19          ++count;
    20          cout<<"jingling"<<count<<"zhiye"<<profession<<"wuqi"<<weapon;
    21  }
    22  int main()
    23  {
    24          Sprite spirit[3];
    25          ifstream rfile("file.data",ios::binary);
    26          if (!rfile)
    27          {
    28                  cout<<"can't open the file.data"<<endl;
    29                  abort();
    30          }
    31
    32          for(int i=0;i<3;i++)
    33          {
    34                  rfile.read((char*)&spirit[i],sizeof(spirit[i]));
    35                  spirit[i].showSprite();
    36
    37          }
    38          rfile.close();
    39          return 0;
    40  }

执行完1和2后，执行结果是：

jingling1zhiyewuqi`˜Ý‚e+ð Pÿÿÿÿÿÿÿÿ!P „Ý‚e+àÝ‚e+ X P( P¸ Pˆ P!Pè P±í*** glibc detected *** m: free(): invalid pointer: 0x00000000005020d0 ***
======= Backtrace: =========
/lib64/libc.so.6[0x2b6582c0a4fe]
/lib64/libc.so.6(__libc_free+0x6c)[0x2b6582c0bb7c]
/usr/lib64/libstdc++.so.6(_ZNSsD1Ev+0x3a)[0x2b65827d9e5a]
m(__gxx_personality_v0+0x494)[0x401094]
m(__gxx_personality_v0+0x41d)[0x40101d]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x2b6582bbc164]
m(__gxx_personality_v0+0x49)[0x400c49]
======= Memory map: ========
00400000-00402000 r-xp 00000000 fd:01 197048                             /home2/billing/wangpanpan/C++/w/m
00501000-00502000 rw-p 00001000 fd:01 197048                             /home2/billing/wangpanpan/C++/w/m
00502000-00523000 rw-p 00502000 00:00 0                                  [heap]
2b6582622000-2b658263d000 r-xp 00000000 08:02 12961                      /lib64/ld-2.4.so
2b658263d000-2b658263f000 rw-p 2b658263d000 00:00 0
2b6582658000-2b6582659000 rw-p 2b6582658000 00:00 0
2b658273c000-2b658273e000 rw-p 0001a000 08:02 12961                      /lib64/ld-2.4.so
2b658273e000-2b6582821000 r-xp 00000000 08:02 17856                      /usr/lib64/libstdc++.so.6.0.8
2b6582821000-2b6582921000 ---p 000e3000 08:02 17856                      /usr/lib64/libstdc++.so.6.0.8
2b6582921000-2b6582927000 r--p 000e3000 08:02 17856                      /usr/lib64/libstdc++.so.6.0.8
2b6582927000-2b658292a000 rw-p 000e9000 08:02 17856                      /usr/lib64/libstdc++.so.6.0.8
2b658292a000-2b658293c000 rw-p 2b658292a000 00:00 0
2b658293c000-2b6582990000 r-xp 00000000 08:02 12976                      /lib64/libm-2.4.so
2b6582990000-2b6582a8f000 ---p 00054000 08:02 12976                      /lib64/libm-2.4.so
2b6582a8f000-2b6582a91000 rw-p 00053000 08:02 12976                      /lib64/libm-2.4.so
2b6582a91000-2b6582a9e000 r-xp 00000000 08:02 17620                      /lib64/libgcc_s.so.1
2b6582a9e000-2b6582b9d000 ---p 0000d000 08:02 17620                      /lib64/libgcc_s.so.1
2b6582b9d000-2b6582b9e000 rw-p 0000c000 08:02 17620                      /lib64/libgcc_s.so.1
2b6582b9e000-2b6582b9f000 rw-p 2b6582b9e000 00:00 0
2b6582b9f000-2b6582cd5000 r-xp 00000000 08:02 12968                      /lib64/libc-2.4.so
2b6582cd5000-2b6582dd5000 ---p 00136000 08:02 12968                      /lib64/libc-2.4.so
2b6582dd5000-2b6582dd8000 r--p 00136000 08:02 12968                      /lib64/libc-2.4.so
2b6582dd8000-2b6582dda000 rw-p 00139000 08:02 12968                      /lib64/libc-2.4.so
2b6582dda000-2b6582de0000 rw-p 2b6582dda000 00:00 0
2b6582e00000-2b6582e21000 rw-p 2b6582e00000 00:00 0
2b6582e21000-2b6582f00000 ---p 2b6582e21000 00:00 0
7fff28471000-7fff28488000 rw-p 7fff28471000 00:00 0                      [stack]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0                  [vdso]
Abort

而且File.data文件的内容是：

X P^@^@^@^@^@( P^@^@^@^@^@¸ P^@^@^@^@^@<88> P^@^@^@^@^@^X!P^@^@^@^@^@è P^@^@^@^@^@

问题2：

我把class类放到了Sprite.h中，然后file1变成了：

#include<iostream>

#include<fstream>

#include "Sprite.h"

using namespace std;

int Sprite::count=0;
void Sprite:: showSprite()
{
        ++count;
        cout<<"jingling:"<<count<<"zhiye:"<<profession<<"wuqi:"<<weapon<<endl;
}

int main()

{

 Sprite sprites[3]={Sprite("fashi","mozhang"),Sprite("zhanshi","tulongbaoda"),Sprite("daoshi","yitianjian")};

 ofstream file("file.data",ios::ate|ios::binary);

 if (!file)

 {

  cout<<"can't open the file"<<endl;

  return 1;

 }

 for (int i=0;i<3;i++)

 {

  file.write((char*)&sprites[i],sizeof(sprites[i]));

 }

file.close();

 

return 0;

 

}

 

Spirit.h文件的内容是：

class Sprite

{

        public:

            Sprite(){};

            Sprite(string profession,string weapon):profession(profession),weapon(weapon){};

             void showSprite();

        private:

                string profession;

                string weapon;

                static int count;

};

 

但是编译的结果怎么报这样的错误呢？

Sprite.h:6: error: expected `)' before ‘profession’
Sprite.h:9: error: ‘string’ does not name a type
Sprite.h:10: error: ‘string’ does not name a type
file4.cpp: In member function ‘void Sprite::showSprite()’:
file4.cpp:9: error: ‘profession’ was not declared in this scope
file4.cpp:9: error: ‘weapon’ was not declared in this scope
file4.cpp: In function ‘int main()’:
file4.cpp:13: error: no matching function for call to ‘Sprite::Sprite(const char [6], const char [8])’
Sprite.h:5: note: candidates are: Sprite::Sprite()
Sprite.h:3: note:                 Sprite::Sprite(const Sprite&)
file4.cpp:13: error: no matching function for call to ‘Sprite::Sprite(const char [8], const char [12])’
Sprite.h:5: note: candidates are: Sprite::Sprite()
Sprite.h:3: note:                 Sprite::Sprite(const Sprite&)
file4.cpp:13: error: no matching function for call to ‘Sprite::Sprite(const char [7], const char [11])’
Sprite.h:5: note: candidates are: Sprite::Sprite()
Sprite.h:3: note:                 Sprite::Sprite(const Sprite&)

 

回答问题1：

    #include<iostream>
    #include<fstream>
 #include<string>
    using namespace std;
      class Sprite
      {
      public:
            Sprite(){};
            Sprite(char *p, char *w){
    strcpy(profession, p);
    strcpy(weapon, w);
   };
           
   void showSprite();
 
            char profession[10];
            char weapon[15];
            static int count;
      };
      int Sprite::count=0;
      void Sprite:: showSprite()
      {
      ++count;
      cout<<"jingling:"<<count<<"zhiye:"<<profession<<"wuqi:"<<weapon<<endl;
      }
 
  
   int main()
      {
       Sprite sprites[3]={Sprite("fashi","mozhang"),Sprite("zhanshi","tulongbaoda"),Sprite("daoshi","yitianjian")};
       ofstream file("file.data",ios::ate|ios::binary);
       if (!file)
       {
        cout<<"can't open the file"<<endl;
        return 1;
       }
       for (int i=0;i<3;i++)
       {
        file.write(sprites[i].profession, strlen(sprites[i].profession));
  file.write("", 1);
  file.write(sprites[i].weapon, strlen(sprites[i].weapon));
  file.write("", 1);
       }
      file.close();
   string a="saasdaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaadsadasdasdada";
   cout<<sizeof(a)<<endl;
      return 0;
   
      }

原因是：string类型不是基本类型，定义为string型的，它的字符串存在堆中，而变量只是存储了指向堆得指针和长度，以及两个指针（读取得地方），所以问题1中是乱码，是读不到指定的内容的