[wxWidgets.git] / docs / latex / wx / datistrm.tex

\section{\class{wxDataInputStream}}\label{wxdatainputstream}

This class provides functions that read binary data types in a
portable way. Data can be read in either big-endian or litte-endian
format, little-endian being the default on all architectures.

If you want to read data from text files (or streams) use 
\helpref{wxTextInputStream}{wxtextinputstream} instead.

The >> operator is overloaded and you can use this class like a standard C++ iostream.
Note, however, that the arguments are the fixed size types wxUint32, wxInt32 etc
and on a typical 32-bit computer, none of these match to the "long" type (wxInt32
is defined as signed int on 32-bit architectures) so that you cannot use long. To avoid
problems (here and elsewhere), make use of the wxInt32, wxUint32, etc types.

For example:

\begin{verbatim}
  wxFileInputStream input( "mytext.dat" );
  wxDataInputStream store( input );
  wxUint8 i1;
  float f2;
  wxString line;

  store >> i1;       // read a 8 bit integer.
  store >> i1 >> f2; // read a 8 bit integer followed by float.
  store >> line;     // read a text line
\end{verbatim}

See also \helpref{wxDataOutputStream}{wxdataoutputstream}. 

\wxheading{Derived from}

None

\wxheading{Include files}

<wx/datstrm.h>

\latexignore{\rtfignore{\wxheading{Members}}}

\membersection{wxDataInputStream::wxDataInputStream}\label{wxdatainputstreamconstr}

\func{}{wxDataInputStream}{\param{wxInputStream\&}{ stream}}

Constructs a datastream object from an input stream. Only read methods will
be available.

\wxheading{Parameters}

\docparam{stream}{The input stream.}

\membersection{wxDataInputStream::\destruct{wxDataInputStream}}

\func{}{\destruct{wxDataInputStream}}{\void}

Destroys the wxDataInputStream object.

\membersection{wxDataInputStream::BigEndianOrdered}

\func{void}{BigEndianOrdered}{\param{bool}{ be\_order}}

If {\it be\_order} is TRUE, all data will be read in big-endian
order, such as written by programs on a big endian architecture 
(e.g. Sparc) or written by Java-Streams (which always use 
big-endian order).
  
\membersection{wxDataInputStream::Read8}

\func{wxUint8}{Read8}{\void}

Reads a single byte from the stream.

\membersection{wxDataInputStream::Read16}

\func{wxUint16}{Read16}{\void}

Reads a 16 bit integer from the stream.

\membersection{wxDataInputStream::Read32}

\func{wxUint32}{Read32}{\void}

Reads a 32 bit integer from the stream.

\membersection{wxDataInputStream::ReadDouble}

\func{double}{ReadDouble}{\void}

Reads a double (IEEE encoded) from the stream.

\membersection{wxDataInputStream::ReadString}

\func{wxString}{ReadString}{\void}

Reads a string from a stream. Actually, this function first reads a long integer
specifying the length of the string (without the last null character) and then
reads the string.
Commit	Line	Data
f6106dae VZ	1	\section{\class{wxDataInputStream}}\label{wxdatainputstream}
	2
	3	This class provides functions that read binary data types in a
	4	portable way. Data can be read in either big-endian or litte-endian
	5	format, little-endian being the default on all architectures.
	6
	7	If you want to read data from text files (or streams) use
	8	\helpref{wxTextInputStream}{wxtextinputstream} instead.
	9
	10	The >> operator is overloaded and you can use this class like a standard C++ iostream.
	11	Note, however, that the arguments are the fixed size types wxUint32, wxInt32 etc
	12	and on a typical 32-bit computer, none of these match to the "long" type (wxInt32
	13	is defined as signed int on 32-bit architectures) so that you cannot use long. To avoid
	14	problems (here and elsewhere), make use of the wxInt32, wxUint32, etc types.
	15
	16	For example:
	17
	18	\begin{verbatim}
	19	wxFileInputStream input( "mytext.dat" );
	20	wxDataInputStream store( input );
	21	wxUint8 i1;
	22	float f2;
	23	wxString line;
	24
	25	store >> i1; // read a 8 bit integer.
	26	store >> i1 >> f2; // read a 8 bit integer followed by float.
	27	store >> line; // read a text line
	28	\end{verbatim}
	29
	30	See also \helpref{wxDataOutputStream}{wxdataoutputstream}.
	31
	32	\wxheading{Derived from}
	33
	34	None
	35
	36	\wxheading{Include files}
	37
	38	<wx/datstrm.h>
	39
	40	\latexignore{\rtfignore{\wxheading{Members}}}
	41
	42	\membersection{wxDataInputStream::wxDataInputStream}\label{wxdatainputstreamconstr}
	43
	44	\func{}{wxDataInputStream}{\param{wxInputStream\&}{ stream}}
	45
	46	Constructs a datastream object from an input stream. Only read methods will
	47	be available.
	48
	49	\wxheading{Parameters}
	50
	51	\docparam{stream}{The input stream.}
	52
	53	\membersection{wxDataInputStream::\destruct{wxDataInputStream}}
	54
	55	\func{}{\destruct{wxDataInputStream}}{\void}
	56
	57	Destroys the wxDataInputStream object.
	58
	59	\membersection{wxDataInputStream::BigEndianOrdered}
	60
	61	\func{void}{BigEndianOrdered}{\param{bool}{ be\_order}}
	62
	63	If {\it be\_order} is TRUE, all data will be read in big-endian
	64	order, such as written by programs on a big endian architecture
65	(e.g. Sparc) or written by Java-Streams (which always use
66	big-endian order).
67
68	\membersection{wxDataInputStream::Read8}
69
70	\func{wxUint8}{Read8}{\void}
71
72	Reads a single byte from the stream.
73
74	\membersection{wxDataInputStream::Read16}
75
76	\func{wxUint16}{Read16}{\void}
77
78	Reads a 16 bit integer from the stream.
79
80	\membersection{wxDataInputStream::Read32}
81
82	\func{wxUint32}{Read32}{\void}
83
84	Reads a 32 bit integer from the stream.
85
86	\membersection{wxDataInputStream::ReadDouble}
87
88	\func{double}{ReadDouble}{\void}
89
90	Reads a double (IEEE encoded) from the stream.
91
92	\membersection{wxDataInputStream::ReadString}
93
94	\func{wxString}{ReadString}{\void}
95
96	Reads a string from a stream. Actually, this function first reads a long integer
97	specifying the length of the string (without the last null character) and then
98	reads the string.
99
100