博客
关于我
CStdioFile总结
阅读量:669 次
发布时间:2019-03-16

本文共 2697 字,大约阅读时间需要 8 分钟。

 

CStdioFile继承自CFile.

参数内容:

第一个参数为路径+文件名,最后一个为错误出现的结构.

现在解释下第二个参数

CFile::modeCreate   Directs the constructor to create a new file. If the file exists already, it is truncated to 0 length.

指定构造器创建一个新的文件,如果文件已经存在,则内容截0.

CFile::modeNoTruncate   Combine this value with modeCreate. If the file being created already exists, it is not truncated to 0 length. Thus the file is guaranteed 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.

modeNoTruncate

假如你不用这个参数的话,用modeCreate模式创建和打开一个文件,假如这个文件已经存在,则会清空这个已经存在的文件,加上modeNoTruncate的话,就不会清空这个文件了

CFile::modeRead   Opens the file for reading only.

只是以读取方式打开

CFile::modeReadWrite   Opens the file for reading and writing.

读与写同时

CFile::modeWrite   Opens the file for writing only.

只写

CFile::modeNoInherit   Prevents the file from being inherited by child processes.

阻止这个文件被子进程继承

CFile::shareDenyNone   Opens the file without denying other processes read or write access to the file. Create fails if the file has been opened in compatibility mode by any other process.

打开这个文件同时允许其它进程读写这个文件。如果文件被其它进程以incompatibility模式打开,这是create操作会失败。

CFile::shareDenyRead   Opens the file and denies other processes read access to the file. Create fails if the file has been opened in compatibility mode or for read access by any other process.

打开文件拒绝其它任何进程读这个文件。如果文件被其它进程用compatibility模式或者是读方式打开,create操作失败。

CFile::shareDenyWrite   Opens the file and denies other processes write access to the file. Create fails if the file has been opened in compatibility mode or for write access by any other process.

打开文件拒绝其它任何进程写这个文件。如果文件被其它进程用compatibility模式或者是写方式打开,create操作失败。

CFile::shareExclusive   Opens the file with exclusive mode, denying other processes both read and write access to the file. Construction fails if the file has been opened in any other mode for read or write access, even by the current process.

以独占方式打开这个文件,不允许其它进程读写这个文件。

CFile::shareCompat   This flag is not available in 32 bit MFC. This flag maps to CFile::shareExclusive when used in CFile::Open.

这个标志在32位的MFC中无效。

CFile::typeText   Sets text mode with special processing for carriage return–linefeed pairs (used in derived classes only).

CFile::typeText   设置成对回车换行对有特殊处理的文本模式(仅用在派生类中)

CFile::typeBinary   设置二进制模式(仅用在派生类中)

CStdioFile::ReadString

virtual LPTSTR ReadString( LPTSTR lpsz, UINT nMax );

throw( CFileException );

BOOL ReadString(CString& rString);

throw( CFileException );

Return Value

A pointer to the buffer containing the text data. NULL if end-of-file was reached without reading any data; or if boolean, FALSE if end-of-file was reached without reading any data.

 

转载地址:http://nlaqz.baihongyu.com/

你可能感兴趣的文章
MySQL万字总结!超详细!
查看>>
Mysql下载以及安装(新手入门,超详细)
查看>>
MySQL不会性能调优?看看这份清华架构师编写的MySQL性能优化手册吧
查看>>
MySQL不同字符集及排序规则详解:业务场景下的最佳选
查看>>
Mysql不同官方版本对比
查看>>
MySQL与Informix数据库中的同义表创建:深入解析与比较
查看>>
mysql与mem_细说 MySQL 之 MEM_ROOT
查看>>
MySQL与Oracle的数据迁移注意事项,另附转换工具链接
查看>>
mysql丢失更新问题
查看>>
MySQL两千万数据优化&迁移
查看>>
MySql中 delimiter 详解
查看>>
MYSQL中 find_in_set() 函数用法详解
查看>>
MySQL中auto_increment有什么作用?(IT枫斗者)
查看>>
MySQL中B+Tree索引原理
查看>>
mysql中cast() 和convert()的用法讲解
查看>>
mysql中datetime与timestamp类型有什么区别
查看>>
MySQL中DQL语言的执行顺序
查看>>
mysql中floor函数的作用是什么?
查看>>
MySQL中group by 与 order by 一起使用排序问题
查看>>
mysql中having的用法
查看>>