如果不存在，则需要创建一个文件 [英] Need to create a file if it does not exist

问题描述

大家好，
我有一个查询，我需要编写代码，这样我就需要打开一个文件(如果该文件不存在)，则应首先创建然后打开.我这样写的

CStdioFile文件；
file.Open(_strDestination，CFile :: modeReadWrite | CFile :: typeText);
我是这样写的，但没有帮助.


在此先感谢您.

Hi all ,
I have a query , i need to write a code such that I need to open a file if it does not exist it should first create and then open . I wrote this way

CStdioFile file;
file.Open(_strDestination,CFile::modeReadWrite | CFile::typeText);
I wrote it this way but did not help .


Thanks in advance .

推荐答案

CStdioFile file;
file.Open(_strDestination, CFile::modeReadWrite | CFile::typeText | CFile::modeCreate | CFile::modeNoTruncate ); 

CFile :: modeNoTruncate将此值与modeCreate结合在一起.如果正在创建的文件已经存在，则不会将其截短为0.此外，如果正在创建的文件已经存在，则基础文件指针将指向文件的开头.该标志保证文件可以以新创建的文件或现有文件的形式打开.例如，当打开可能不存在的设置文件时，这可能会很有用.此选项也适用于CStdioFile.

CFile::modeNoTruncate Combine this value with modeCreate. If the file being created already exists, it is not truncated to 0 length. Furthermore, if the file being created already exists, the underlying file pointer will point to the beginning of the file. This flag guarantees the file to open, either as a newly created file or as an existing file. This might be useful, for example, when opening a settings file that may or may not exist already. This option applies to CStdioFile as well.

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