使用CStdioFile 读写UNICODE文档



一：写文档

 

1  创建文档并写入内容

CString filePath=L"C:\\unicode.txt";CStdioFile wfile;if (!wfile.Open(filePath,CFile::modeCreate|CFile::modeWrite|CFile::typeBinary)){ AfxMessageBox(L"文件无法修改");return;}WORD sign=0xfeff; // unicode文档 标志wfile.Write(&sign,2);CString fileContent;fileContent=L"UNICODE文档";wfile.Write(fileContent.GetBuffer(),fileContent.GetLength()*2);fileContent.ReleaseBuffer();wfile.Close();

WORD sign=0xfeff;wFile.Write(&sign,2);//遍历list容器  写入文件list<CString>::iterator it=fileList.begin();for (it=fileList.begin();it!=fileList.end();it++){str=*it;//写入CString类型的字符串wFile.Write(str.GetBuffer(),str.GetLength()*2);str.ReleaseBuffer();//使用WriteString 写入回车换行符wFile.WriteString(L"\r\n");}wFile.Close();

2  判断文档是否存在，若存在，则在文档末尾添加内容，若不存在，重新创建

CString filePath=L"c:\\test.txt";CStdioFile wfile;CFileFind fileFind;if(!fileFind.FindFile(filePath)// 查找文件是否存在{if (!wfile.Open(filePath,CFile::modeWrite|CFile::modeCreate|CFile::typeBinary)) //unicode 必须以二进制打开return ;WORD sign=0xfeff;wfile.Write(&sign,2);}else  if (!wfile.Open(filePath,CFile::modeWrite|CFile::modeNoTruncate|CFile::typeBinary))return ;WORD sign;wfile.SeekToBegin();wfile.Read(&sign,2);if (sign!=0xfeff){AfxMessageBox(L"不是UNICODE文档");return;}wfile.SeekToEnd();CString  str=L"添加到文档末尾";wfile.Write(str.GetBuffer(),str.GetLength()*2);str.ReleaseBuffer();wfile.Close();

二 读文档：

1 使用Read函数 读取文档 ，并将读取到的内容转换为CString 以方便处理

CString    filepath;  CStdioFile wfile;filepath=L"c:\\test.txt";if (!wfile.Open(filepath,CFile::modeRead|CFile::typeBinary)){AfxMessageBox(L"无法打开文件");return ;}ULONGLONG len=wfile.GetLength();byte *pByte=NULL;if (len>0){pByte=new byte[len];memset(pByte,0,len*sizeof(byte));WORD sign;wfile.SeekToBegin();wfile.Read(&sign,2);if (sign!=0xfeff){AfxMessageBox(L"录入文件不是Unicode");}else{wfile.Read(pByte,len-2);}}else{AfxMessageBox(L"文件长度为0 ");return;}CString buf=(WCHAR*)pByte; // 将数组转换为 CString类型wfile.Close();// 其他操作//...//delete [] pByte; // 释放资源

2 使用 ReadString  读取一行文本

 

virtual LPTSTR ReadString(   LPTSTR lpsz,   UINT nMax );virtual BOOL ReadString(   CString& rString);

 

// 读取到换行符\n为止，且读取的字符少于nMax-1时，将换行符 \n 保存到缓冲区中

Reading is stopped by the first newline character. If, in that case, fewer thannMax–1 characters have been read, a newline character is stored in the buffer. A null character ('\0') is appended in either case.

 

注意：

The CString version of this function removes the '\n' if present; the LPTSTR version does not.

 

ReadString(CString & rString)  中， rString   为：  一行文本+结尾符       

但结尾是 回车符 '\r'  而不是'\r\n'  

 

因此，若想得到这一行数据，还必须将结尾符去掉方可。

 

示例：

WORD sign;readFile.SeekToBegin();readFile.Read(&sign,2);if (sign!=0xfeff){AfxMessageBox(L"file.txt  不是Unicode");}else{CString str;//读取文件while (readFile.ReadString(str)) // 此时，获得的str字符串  含有回车符\r  但是不含换行符\n{// 去掉 回车符 \r  获得不含回车换行符的纯粹的字符串数据str=str.Left(str.GetLength()-1);m_filePathMap.SetAt(str,0);}}

一个综合例子：

CFileDialog  dlg(  TRUE,  _T("*"),   _T("*.txt"),  OFN_FILEMUSTEXIST|OFN_HIDEREADONLY|OFN_ALLOWMULTISELECT,   _T("All Files(*.txt|*.txt||)") );  TCHAR    szbuffer[1024];  szbuffer[0]=0;  dlg.m_ofn.lpstrFile = szbuffer;  dlg.m_ofn.nMaxFile = 1024;  if(IDOK==dlg.DoModal())  {  POSITION   pos = dlg.GetStartPosition();  CString    filepath;  CStdioFile wfile;while(pos!=NULL)  {  filepath = dlg.GetNextPathName(pos);  if (!wfile.Open(filepath,CFile::modeReadWrite|CFile::typeBinary)){AfxMessageBox(L"无法打开文件");return ;}ULONGLONG len=wfile.GetLength();CString  strTxt;byte *pByte=NULL;if (len>0){pByte=new byte[len];WORD sign;wfile.SeekToBegin();wfile.Read(&sign,2);if (sign!=0xfeff){AfxMessageBox(L"录入文件不是Unicode");}else{pByte[len-1]=0;pByte[len-2]=0;wfile.Read(pByte,len-2);EraseTxtMark(pByte,len);}}CString buf=(WCHAR*)pByte;wfile.Close();if (!wfile.Open(filepath,CFile::modeReadWrite|CFile::typeBinary|CFile::modeCreate)){AfxMessageBox(L"无法打开文件");return ;}wfile.SeekToBegin();WORD sign=0xfeff;wfile.Write(&sign,2);wfile.Write(buf.GetBuffer(),buf.GetLength()*2);wfile.Close();delete [] pByte;}  }