wxDataInputStream

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

If you want to read data from text files (or streams) use 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:

  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

See also wxDataOutputStream.

Derived from

None

Include files

<wx/datstrm.h>



wxDataInputStream::wxDataInputStream



wxDataInputStream(wxInputStream& stream)



wxDataInputStream(wxInputStream& stream, wxMBConv& conv = wxMBConvUTF8)

Constructs a datastream object from an input stream. Only read methods will be available. The second form is only available in Unicode build of wxWidgets.

Parameters

stream
The input stream.

conv
Charset conversion object object used to decode strings in Unicode mode (see wxDataInputStream::ReadString documentation for detailed description). Note that you must not destroy conv before you destroy this wxDataInputStream instance!



wxDataInputStream::~wxDataInputStream



~wxDataInputStream(void)

Destroys the wxDataInputStream object.



wxDataInputStream::BigEndianOrdered



void BigEndianOrdered(bool be_order)

If 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).



wxDataInputStream::Read8



wxUint8 Read8(void)

Reads a single byte from the stream.



void Read8(wxUint8 * buffer, size_t size)

Reads bytes from the stream in a specified buffer. The amount of bytes to read is specified by the size variable.



wxDataInputStream::Read16



wxUint16 Read16(void)

Reads a 16 bit unsigned integer from the stream.



void Read16(wxUint16 * buffer, size_t size)

Reads 16 bit unsigned integers from the stream in a specified buffer. the amount of 16 bit unsigned integer to read is specified by the size variable.



wxDataInputStream::Read32



wxUint32 Read32(void)

Reads a 32 bit unsigned integer from the stream.



void Read32(wxUint32 * buffer, size_t size)

Reads 32 bit unsigned integers from the stream in a specified buffer. the amount of 32 bit unsigned integer to read is specified by the size variable.



wxDataInputStream::Read64



wxUint64 Read64(void)

Reads a 64 bit unsigned integer from the stream.



void Read64(wxUint64 * buffer, size_t size)

Reads 64 bit unsigned integers from the stream in a specified buffer. the amount of 64 bit unsigned integer to read is specified by the size variable.



wxDataInputStream::ReadDouble



double ReadDouble(void)

Reads a double (IEEE encoded) from the stream.



void ReadDouble(double * buffer, size_t size)

Reads double data (IEEE encoded) from the stream in a specified buffer. the amount of double to read is specified by the size variable.



wxDataInputStream::ReadString



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.

In Unicode build of wxWidgets, the fuction first reads multibyte (char*) string from the stream and then converts it to Unicode using the conv object passed to constructor and returns the result as wxString. You are responsible for using the same convertor as when writing the stream.

See also wxDataOutputStream::WriteString.

ymasuda 平成17年11月19日