The QDataStream class provides basic functions for serialization of binary data to a QIODevice. (details) (complete member list)
#include <qdstream.h>
A data stream is a binary stream of encoded information which is 100% independent of the host computer operation system, CPU or byte order. A stream that is written by a PC under DOS/Windows can easily be read by a Sun SPARC running Solaris.
The QDataStream class implements serialization of primitive types,
like char,
short,
int,
char*
etc. Serialization of more
complex data is accomplished by breaking up the data into primitive units.
The programmer can select which byte order to use when serializing data. The default setting is big endian (MSB first). Changing it to little endian (LSB first) breaks the portability. We therefore recommend keeping this setting unless you have special needs or requirements.
A data stream cooperates closely with a QIODevice. A QIODevice represents an input/output medium one can read data from and write data to. The QFile class is an example of an IO device.
Example of how to serialize to a stream:
QFile f( "file.dta" );
f.open( IO_WriteOnly ); // open file for writing
QDataStream s( &f ); // serialize using f
s << "the answer is"; // serialize string
s << 42; // serialize integer
f.close(); // done
Example of how to serialize from a stream:
QFile f( "file.dta" );
f.open( IO_ReadOnly ); // open file for reading
QDataStream s( &f ); // serialize using f
char *str;
int a;
s >> str >> a; // "the answer is" and 42
f.close(); // done
delete str; // delete string
See also: QTextStream.
Constructs a data stream that has no IO device.
Constructs a data stream that uses the IO device d.
Destroys the data stream.
The destructor will not affect the current IO device.
Returns the current byte order setting.
See also: setByteOrder().
Returns the IO device currently set.
Returns TRUE if the IO device has reached the end position (end of stream) or if there is no IO device set.
Returns FALSE if the current position of the read/write head of the IO device is somewhere before the end position.
Returns TRUE if the printable data flag has been set.
See also: setPrintableData().
Writen an unsigned byte to the stream and returns a reference to the stream.
Writes a signed byte to the stream.
Writes an unsigned 16-bit integer to the stream and returns a reference to the stream.
Writes a signed 16-bit integer to the stream and returns a reference to the stream.
Writes an unsigned 32-bit integer to the stream and returns a reference to the stream.
Writes a signed 32-bit integer to the stream and returns a reference to the stream.
Writes an unsigned integer to the stream as a 32-bit unsigned integer (UINT32). Returns a reference to the stream.
Writes a signed integer to the stream as a 32-bit signed integer (INT32). Returns a reference to the stream.
Writes a 32-bit floating point number to the stream using the standard IEEE754 format. Returns a reference to the stream.
Writes a 64-bit floating point number to the stream using the standard IEEE754 format. Returns a reference to the stream.
Writes the '\0'-terminated string s to the stream and returns a reference to the stream.
The string is serialized using writeBytes().
Reads an unsigned byte from the stream and returns a reference to the stream.
Reads a signed byte from the stream.
Reads an unsigned 16-bit integer from the stream and returns a reference to the stream.
Reads a signed 16-bit integer from the stream and returns a reference to the stream.
Reads an unsigned 32-bit integer from the stream and returns a reference to the stream.
Reads a signed 32-bit integer from the stream and returns a reference to the stream.
Reads a signed integer from the stream as a 32-bit signed integer (INT32). Returns a reference to the stream.
Reads an unsigned integer from the stream as a 32-bit unsigned integer (UINT32). Returns a reference to the stream.
Reads a 32-bit floating point number from the stream using the standard IEEE754 format. Returns a reference to the stream.
Reads a 64-bit floating point number from the stream using the standard IEEE754 format. Returns a reference to the stream.
Reads the '\0'-terminated string s from the stream and returns a reference to the stream.
The string is read using readBytes().
Reads the buffer s from the stream and returns a reference to the stream.
The buffer s will be allocated with new.
Destroy it with the
delete
operator.
If s cannot be allocated, s will be set to 0.
The l parameter will be set to the length of the buffer.
The serialization format is an UINT32 length specifier first, then the data (length bytes).
See also: readRawBytes().
Reads len bytes from the stream into e s and returns a reference to the stream.
The buffer s must be preallocated.
See also: readBytes() and QIODevice::readBlock().
Sets the serialization byte order to bo.
The bo parameter can be QDataStream::BigEndian or QDataStream::LittleEndian.
The default setting is big endian. We recommend leaving this setting unless you have special requirements.
Sets the IO device to d.
Sets or clears the printable data flag.
If this flag is set, the write functions will generate output that consists of printable characters (7 bit ASCII).
We recommend enabling printable data only for debugging purposes (it is slower and creates bigger output).
Unsets the IO device. This is the same as calling setDevice( 0 ).
Writes the length specifier len and the buffer s to the stream and returns a reference to the stream.
The len is serialized as an UINT32, followed by len bytes from s.
See also: writeRawBytes().
Writes len bytes from s to the stream and returns a reference to the stream.
The len is serialized as an UINT32, followed by len bytes from s.
See also: writeBytes(), QIODevice::writeBlock().
This file is part of the Qt toolkit, copyright 1995 Troll Tech, all rights reserved.
It was generated from the following files: