qiodevice.3qt

Trolltech公司发布的基于C++图形开发环境

Reimplemented in QSocketDevice, QBuffer, QSocket and QFile.
.SH "int QIODevice::at () const \fC[virtual]\fR"
Virtual function that returns the current I/O device index.
.PP
This index is the data read/write head of the I/O device.
.PP
See also size().
.PP
Reimplemented in QFile, QBuffer, QSocket and QSocketDevice.
.SH "bool QIODevice::atEnd () const \fC[virtual]\fR"
Virtual function that returns TRUE if the I/O device index is at the end of the input.
.PP
Reimplemented in QSocket, QFile and QSocketDevice.
.SH "void QIODevice::close () \fC[virtual]\fR"
Closes the I/O device.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also open().
.PP
Reimplemented in QSocket, QBuffer, QFile and QSocketDevice.
.SH "int QIODevice::flags () const"
Returns the current I/O device flags setting.
.PP
Flags consists of mode flags and state flags.
.PP
See also mode() and state().
.SH "void QIODevice::flush () \fC[virtual]\fR"
Flushes an open I/O device.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
Reimplemented in QBuffer, QFile, QSocket and QSocketDevice.
.SH "int QIODevice::getch () \fC[virtual]\fR"
Reads a single byte/character from the I/O device.
.PP
Returns the byte/character read, or -1 if the end of the I/O device has been reached.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also putch() and ungetch().
.PP
Reimplemented in QBuffer, QFile, QSocket and QSocketDevice.
.SH "bool QIODevice::isAsynchronous () const"
Returns TRUE if the I/O device is a asynchronous device, otherwise FALSE.
.PP
This mode is currently not in use.
.PP
See also isSynchronous().
.SH "bool QIODevice::isBuffered () const"
Returns TRUE if the I/O device is a buffered (not raw) device, otherwise FALSE.
.PP
See also isRaw().
.SH "bool QIODevice::isCombinedAccess () const"
Returns TRUE if the I/O device is a combined access (both direct and sequential) device, otherwise FALSE.
.PP
This access method is currently not in use.
.SH "bool QIODevice::isDirectAccess () const"
Returns TRUE if the I/O device is a direct access (not sequential) device, otherwise FALSE.
.PP
See also isSequentialAccess().
.SH "bool QIODevice::isInactive () const"
Returns TRUE if the I/O device state is 0, i.e. the device is not open.
.PP
See also isOpen().
.SH "bool QIODevice::isOpen () const"
Returns TRUE if the I/O device state has been opened, otherwise FALSE.
.PP
See also isInactive().
.SH "bool QIODevice::isRaw () const"
Returns TRUE if the I/O device is a raw (not buffered) device, otherwise FALSE.
.PP
See also isBuffered().
.SH "bool QIODevice::isReadWrite () const"
Returns TRUE if the I/O device was opened using \fCIO_ReadWrite\fR mode.
.PP
See also isReadable() and isWritable().
.SH "bool QIODevice::isReadable () const"
Returns TRUE if the I/O device was opened using \fCIO_ReadOnly\fR or \fCIO_ReadWrite\fR mode.
.PP
See also isWritable() and isReadWrite().
.SH "bool QIODevice::isSequentialAccess () const"
Returns TRUE if the I/O device is a sequential access (not direct) device, otherwise FALSE. Operations involving size() and at(int) are not valid on sequential devices.
.PP
See also isDirectAccess().
.SH "bool QIODevice::isSynchronous () const"
Returns TRUE if the I/O device is a synchronous device, otherwise FALSE.
.PP
See also isAsynchronous().
.SH "bool QIODevice::isTranslated () const"
Returns TRUE if the I/O device translates carriage-return and linefeed characters.
.PP
A QFile is translated if it is opened with the \fCIO_Translate\fR mode flag.
.SH "bool QIODevice::isWritable () const"
Returns TRUE if the I/O device was opened using \fCIO_WriteOnly\fR or \fCIO_ReadWrite\fR mode.
.PP
See also isReadable() and isReadWrite().
.SH "int QIODevice::mode () const"
Returns bits OR'ed together that specify the current operation mode.
.PP
These are the flags that were given to the open() function.
.PP
The flags are: \fCIO_ReadOnly, IO_WriteOnly, IO_ReadWrite, IO_Append, IO_Truncate\fR and \fCIO_Translate.\fR
.SH "bool QIODevice::open ( int mode ) \fC[virtual]\fR"
Opens the I/O device using the specified \fImode.\fR Returns TRUE if successful, or FALSE if the device could not be opened.
.PP
The mode parameter \fIm\fR must be a combination of the following flags.
.TP
\fCIO_Raw\fR specified raw (unbuffered) file access.
.TP
\fCIO_ReadOnly\fR opens a file in read-only mode.
.TP
\fCIO_WriteOnly\fR opens a file in write-only mode.
.TP
\fCIO_ReadWrite\fR opens a file in read/write mode.
.TP
\fCIO_Append\fR sets the file index to the end of the file.
.TP
\fCIO_Truncate\fR truncates the file.
.TP
\fCIO_Translate\fR enables carriage returns and linefeed translation for text files under MS-DOS, Window, OS/2 and Macintosh. On Unix systems this flag has no effect. Use with caution as it will also transform every linefeed written to the file into a CRLF pair. This is likely to corrupt your file when writing binary data to it. Cannot be combined with \fCIO_Raw.\fR
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also close().
.PP
Reimplemented in QFile, QSocketDevice, QSocket and QBuffer.
.SH "int QIODevice::putch ( int ch ) \fC[virtual]\fR"
Writes the character \fIch\fR to the I/O device.
.PP
Returns \fIch,\fR or -1 if some error occurred.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also getch() and ungetch().
.PP
Reimplemented in QSocketDevice, QFile, QBuffer and QSocket.
.SH "QByteArray QIODevice::readAll ()"
This convenience function returns all of the remaining data in the device. Note that this only works for direct access devices, such as QFile.
.PP
See also isDirectAccess().
.SH "int QIODevice::readBlock ( char * data, uint maxlen ) \fC[virtual]\fR"
Reads at most \fImaxlen\fR bytes from the I/O device into \fIdata\fR and returns the number of bytes actually read.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also writeBlock().
.PP
Reimplemented in QBuffer, QSocket, QSocketDevice and QFile.
.SH "int QIODevice::readLine ( char * data, uint maxlen ) \fC[virtual]\fR"
Reads a line of text, up to \fImaxlen\fR bytes including a terminating \\0. If there is a newline at the end if the line, it is not stripped.
.PP
Returns the number of bytes read including the terminating \\0, or -1 in case of error.
.PP
This virtual function can be reimplemented much more efficiently by the most subclasses.
.PP
See also readBlock() and QTextStream::readLine().
.PP
Reimplemented in QBuffer, QFile and QSocket.
.SH "bool QIODevice::reset ()"
Sets the device index to 0.
.PP
See also at().
.SH "void QIODevice::resetStatus ()"
Sets the I/O device status to \fCIO_Ok.\fR
.PP
See also status().
.SH "uint QIODevice::size () const \fC[virtual]\fR"
Virtual function that returns the size of the I/O device.
.PP
See also at().
.PP
Reimplemented in QFile, QBuffer, QSocket and QSocketDevice.
.SH "int QIODevice::state () const"
Returns bits OR'ed together that specify the current state.
.PP
The flags are: \fCIO_Open.\fR
.PP
Subclasses may define more flags.
.SH "int QIODevice::status () const"
Returns the I/O device status.
.PP
The I/O device status returns an error code. If open() returns FALSE or readBlock() or writeBlock() return -1, this function can be called to get the reason why the operation did not succeed.
.PP
The status codes are:
.TP
\fCIO_Ok\fR The operation was successful.
.TP
\fCIO_ReadError\fR Could not read from the device.
.TP
\fCIO_WriteError\fR Could not write to the device.
.TP
\fCIO_FatalError\fR A fatal unrecoverable error occurred.
.TP
\fCIO_OpenError\fR Could not open the device.
.TP
\fCIO_ConnectError\fR Could not connect to the device.
.TP
\fCIO_AbortError\fR The operation was unexpectedly aborted.
.TP
\fCIO_TimeOutError\fR The operation timed out.
.TP
\fCIO_UnspecifiedError\fR An unspecified error happened on close.
.PP
See also resetStatus().
.SH "int QIODevice::ungetch ( int ch ) \fC[virtual]\fR"
Puts the character \fIch\fR back into the I/O device and decrements the index if it is not zero.
.PP
This function is normally called to "undo" a getch() operation.
.PP
Returns \fIch,\fR or -1 if some error occurred.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also getch() and putch().
.PP
Reimplemented in QSocket, QBuffer, QSocketDevice and QFile.
.SH "int QIODevice::writeBlock ( const QByteArray & data )"
This convenience function is the same as calling writeBlock( data.data(), data.size() ).
.SH "int QIODevice::writeBlock ( const char * data, uint len ) \fC[virtual]\fR"
Writes \fIlen\fR bytes from \fIp\fR to the I/O device and returns the number of bytes actually written.
.PP
This virtual function must be reimplemented by all subclasses.
.PP
See also readBlock().
.PP
Reimplemented in QSocketDevice, QBuffer, QFile and QSocket.
.SH "void QIODevice::setFlags ( int f ) \fC[protected]\fR"
For internal use only.
.SH "void QIODevice::setMode ( int m ) \fC[protected]\fR"
For internal use only.
.SH "void QIODevice::setState ( int s ) \fC[protected]\fR"
For internal use only.
.SH "void QIODevice::setStatus ( int s ) \fC[protected]\fR"
For internal use only.
.SH "void QIODevice::setType ( int t ) \fC[protected]\fR"
For internal use only.
.SH "SEE ALSO"
.BR http://doc.trolltech.com/qiodevice.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports make our job much simpler. Thank you.
.P
In case of content or formattting problems with this manual page, please
report them to
.BR [e-mail] .
Please include the name of the manual page (qiodevice.3qt) and the Qt
version (2.3.10).