20091113 08:37 实现文件读写操作的几种方法

实现文件读写操作的几种方法

下面为实现文件读取数据的代码：

//以下为用C语言读取文件

FILE *pfile=fopen("2.txt","r");

       char *pbuf;

       fseek(pfile,0,SEEK_END);

       long len=ftell(pfile);

       pbuf=new char[len+1];

       pbuf[len]=0;

       rewind(pfile);

       fread(pbuf,1,len,pfile);

       MessageBox(pbuf);

       fclose(pfile);

       //以下为用C++语言读取文件

       char ch[100];

       memset(ch,0,100);

       ifstream ifs("3.txt");

       ifs.read(ch,100);

       MessageBox(ch);

       ifs.close();

       //以下为用WIN32 API读取文件

       HANDLE hfile;

       hfile=CreateFile("4.txt",GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);

    char ch[100];

       DWORD reads;

       ReadFile(hfile,ch,100,&reads,NULL);

       ch[reads]=0;

       MessageBox(ch);

    CloseHandle(hfile);

       //以下为用MFC读取文件

       CFile file("5.txt",CFile::modeRead);

       char *pbuf;

       DWORD len;

       len=file.GetLength();

       pbuf=new char[len+1];

       pbuf[len]=0;

       file.Read(pbuf,len);

       MessageBox(pbuf);

       file.Close();

下面为实现文件写入数据的代码：

FILE *pfile=fopen("1.txt","w");

       fwrite("Hello,every one!",1,strlen("Hello,every one!"),pfile);

       fflush(pfile);

       fclose(pfile);

   

       //以下为用C++语言写入文件

       ofstream ofs("3.txt");

       ofs.write("Please help me!",strlen("Please help me!"));

       ofs.close();*/

       //以下为用WIN32 API写入文件

       HANDLE hfile;

       hfile=CreateFile("4.txt",GENERIC_WRITE,0,NULL,CREATE_NEW,FILE_ATTRIBUTE_NORMAL,NULL);

       DWORD written;

       WriteFile(hfile,"welcome!",strlen("welcome!"),&written,NULL);

       CloseHandle(hfile);

       //以下为用MFC写入文件

       CFile file("5.txt",CFile::modeCreate|CFile::modeWrite);

       file.Write("Tomorrow is anthor day!",strlen("Tomorrow is anthor day!"));

       file.Close();