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Eneboo - Documentación para desarrolladores
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Eneboo - Documentación para desarrolladores
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The QTextStream class provides basic functions for reading and writing text using a QIODevice. Más...
#include <qtextstream.h>
The QTextStream class provides basic functions for reading and writing text using a QIODevice.
The text stream class has a functional interface that is very similar to that of the standard C++ iostream class.
Qt provides several global functions similar to the ones in iostream: Function Meaning bin sets the QTextStream to read/write binary numbers oct sets the QTextStream to read/write octal numbers dec sets the QTextStream to read/write decimal numbers hex sets the QTextStream to read/write hexadecimal numbers endl forces a line break flush forces the QIODevice to flush any buffered data ws eats any available whitespace (on input) reset resets the QTextStream to its default mode (see reset()) qSetW(int) sets the field width to the given argument qSetFill(int) sets the fill character to the given argument qSetPrecision(int) sets the precision to the given argument
The QTextStream class reads and writes text; it is not appropriate for dealing with binary data (but QDataStream is).
By default, output of Unicode text (i.e. QString) is done using the local 8-bit encoding. This can be changed using the setEncoding() method. For input, the QTextStream will auto-detect standard Unicode "byte order marked" text files; otherwise the local 8-bit encoding is used.
The QIODevice is set in the constructor, or later using setDevice(). If the end of the input is reached atEnd() returns TRUE. Data can be read into variables of the appropriate type using the operator>>() overloads, or read in its entirety into a single string using read(), or read a line at a time using readLine(). Whitespace can be skipped over using skipWhiteSpace(). You can set flags for the stream using flags() or setf(). The stream also supports width(), precision() and fill(); use reset() to reset the defaults.
| anonymous enum |
| anonymous enum |
Locale Latin1 Unicode UnicodeNetworkOrder UnicodeReverse RawUnicode UnicodeUTF8
See setEncoding() for an explanation of the encodings.
| QTextStream::QTextStream | ( | ) |
Constructs a data stream that has no IO device.
| QTextStream::QTextStream | ( | QIODevice * | iod | ) |
Constructs a text stream that uses the IO device iod.
Constructs a text stream that operates on the Unicode QString, str, through an internal device. The filemode argument is passed to the device's open() function; see {QIODevice::mode()}.
If you set an encoding or codec with setEncoding() or setCodec(), this setting is ignored for text streams that operate on QString.
Example:
QString str; QTextStream ts( &str, IO_WriteOnly ); ts << "pi = " << 3.14; // str == "pi = 3.14"
Writing data to the text stream will modify the contents of the string. The string will be expanded when data is written beyond the end of the string. Note that the string will not be truncated:
QString str = "pi = 3.14"; QTextStream ts( &str, IO_WriteOnly ); ts << "2+2 = " << 2+2; // str == "2+2 = 414"
Note that because QString is Unicode, you should not use readRawBytes() or writeRawBytes() on such a stream.
This constructor is equivalent to the constructor taking a QString* parameter.
| QTextStream::QTextStream | ( | QByteArray | a, |
| int | mode | ||
| ) |
Constructs a text stream that operates on the byte array, a, through an internal QBuffer device. The mode argument is passed to the device's open() function; see {QIODevice::mode()}.
Example:
QByteArray array; QTextStream ts( array, IO_WriteOnly ); ts << "pi = " << 3.14 << '\0'; // array == "pi = 3.14"
Writing data to the text stream will modify the contents of the array. The array will be expanded when data is written beyond the end of the string.
Same example, using a QBuffer:
QByteArray array; QBuffer buf( array ); buf.open( IO_WriteOnly ); QTextStream ts( &buf ); ts << "pi = " << 3.14 << '\0'; // array == "pi = 3.14" buf.close();
| QTextStream::QTextStream | ( | FILE * | fh, |
| int | mode | ||
| ) |
Constructs a text stream that operates on an existing file handle fh through an internal QFile device. The mode argument is passed to the device's open() function; see {QIODevice::mode()}.
Note that if you create a QTextStream cout or another name that is also used for another variable of a different type, some linkers may confuse the two variables, which will often cause crashes.
| QTextStream::~QTextStream | ( | ) | [virtual] |
Destroys the text stream.
The destructor does not affect the current IO device.
| QTextStream::QTextStream | ( | ) |
| QTextStream::QTextStream | ( | QIODevice * | ) |
| QTextStream::QTextStream | ( | QByteArray | , |
| int | mode | ||
| ) |
| QTextStream::QTextStream | ( | FILE * | , |
| int | mode | ||
| ) |
| virtual QTextStream::~QTextStream | ( | ) | [virtual] |
| bool QTextStream::atEnd | ( | ) | const [inline] |
Returns TRUE if the IO device has reached the end position (end of the stream or file) or if there is no IO device set; otherwise returns FALSE.
| bool QTextStream::atEnd | ( | ) | const |
| QTextCodec* QTextStream::codec | ( | ) |
| QTextCodec * QTextStream::codec | ( | ) |
Returns the codec actually used for this stream.
If Unicode is automatically detected in input, a codec with name() "ISO-10646-UCS-2" is returned.
| QIODevice * QTextStream::device | ( | ) | const [inline] |
Returns the IO device currently set.
| QIODevice* QTextStream::device | ( | ) | const |
| bool QTextStream::eof | ( | ) | const [inline] |
This function has been renamed to atEnd().
| bool QTextStream::eof | ( | ) | const |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta.
Sets the fill character to f. Returns the previous fill character.
| int QTextStream::fill | ( | ) | const |
| int QTextStream::fill | ( | ) | const [inline] |
Returns the fill character. The default value is ' ' (space).
| int QTextStream::flags | ( | ) | const [inline] |
Returns the current stream flags. The default value is 0.
Flag Meaning skipws Not currently used; whitespace always skipped left Numeric fields are left-aligned right Not currently used (by default, numerics are right-aligned) internal Puts any padding spaces between +/- and value bin Output and input only in binary oct Output and input only in octal dec Output and input only in decimal hex Output and input only in hexadecimal showbase Annotates numeric outputs with 0b, 0, or 0x if in bin, oct, or hex format showpoint Not currently used uppercase Uses 0B and 0X rather than 0b and 0x showpos Shows + for positive numeric values scientific Uses scientific notation for floating point values fixed Uses fixed-point notation for floating point values
Note that unless bin, oct, dec, or hex is set, the input base is octal if the value starts with 0, hexadecimal if it starts with 0x, binary if it starts with 0b, and decimal otherwise.
| int QTextStream::flags | ( | ) | const |
| QTextStream & QTextStream::operator<< | ( | const char * | s | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes a string to the stream and returns a reference to the stream.
The string s is assumed to be Latin1 encoded independent of the Encoding set for the QTextStream.
| QTextStream & QTextStream::operator<< | ( | const QString & | s | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes s to the stream and returns a reference to the stream.
| QTextStream& QTextStream::operator<< | ( | void * | ) |
| QTextStream & QTextStream::operator<< | ( | const QCString & | s | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes s to the stream and returns a reference to the stream.
The string s is assumed to be Latin1 encoded independent of the Encoding set for the QTextStream.
| QTextStream& QTextStream::operator<< | ( | const QString & | ) |
| QTextStream & QTextStream::operator<< | ( | void * | ptr | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes a pointer to the stream and returns a reference to the stream.
The ptr is output as an unsigned long hexadecimal integer.
| QTextStream& QTextStream::operator<< | ( | QChar | ) |
| QTextStream& QTextStream::operator<< | ( | char | ) |
| QTextStream& QTextStream::operator<< | ( | signed | short | ) |
| QTextStream& QTextStream::operator<< | ( | unsigned | short | ) |
| QTextStream& QTextStream::operator<< | ( | signed | int | ) |
| QTextStream& QTextStream::operator<< | ( | unsigned | int | ) |
| QTextStream& QTextStream::operator<< | ( | signed | long | ) |
| QTextStream& QTextStream::operator<< | ( | unsigned | long | ) |
| QTextStream& QTextStream::operator<< | ( | float | ) |
| QTextStream& QTextStream::operator<< | ( | double | ) |
| QTextStream & QTextStream::operator<< | ( | QChar | c | ) |
Writes character char to the stream and returns a reference to the stream.
The character c is assumed to be Latin1 encoded independent of the Encoding set for the QTextStream.
| QTextStream& QTextStream::operator<< | ( | const char * | ) |
| QTextStream& QTextStream::operator<< | ( | const QCString & | ) |
| QTextStream & QTextStream::operator<< | ( | char | c | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes character c to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | unsigned short | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes an unsigned short integer i to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | signed short | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes a short integer i to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | signed int | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes an int i to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | unsigned int | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes an unsigned int i to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | unsigned long | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes an unsigned long int i to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | signed long | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes a long int i to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | float | f | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes a float f to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator<< | ( | double | f | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Writes a double f to the stream and returns a reference to the stream.
| QTextStream & QTextStream::operator>> | ( | unsigned short & | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads an unsigned short integer i from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream& QTextStream::operator>> | ( | unsigned short & | ) |
| QTextStream& QTextStream::operator>> | ( | signed int & | ) |
| QTextStream & QTextStream::operator>> | ( | unsigned long & | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads an unsigned long int i from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream& QTextStream::operator>> | ( | unsigned int & | ) |
| QTextStream & QTextStream::operator>> | ( | float & | f | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a float f from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream& QTextStream::operator>> | ( | unsigned long & | ) |
| QTextStream& QTextStream::operator>> | ( | double & | ) |
| QTextStream& QTextStream::operator>> | ( | QString & | ) |
| QTextStream& QTextStream::operator>> | ( | QCString & | ) |
| QTextStream & QTextStream::operator>> | ( | QChar & | c | ) |
Reads a char c from the stream and returns a reference to the stream. Note that whitespace is not skipped.
| QTextStream & QTextStream::operator>> | ( | QCString & | str | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a "word" from the stream into str and returns a reference to the stream.
A word consists of characters for which isspace() returns FALSE.
| QTextStream & QTextStream::operator>> | ( | char * | s | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a "word" from the stream into s and returns a reference to the stream.
A word consists of characters for which isspace() returns FALSE.
| QTextStream& QTextStream::operator>> | ( | char * | ) |
| QTextStream & QTextStream::operator>> | ( | QString & | str | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a "word" from the stream into str and returns a reference to the stream.
A word consists of characters for which isspace() returns FALSE.
| QTextStream & QTextStream::operator>> | ( | double & | f | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a double f from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream & QTextStream::operator>> | ( | signed short & | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a signed short integer i from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream & QTextStream::operator>> | ( | char & | c | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a char c from the stream and returns a reference to the stream. Note that whitespace is skipped.
| QTextStream& QTextStream::operator>> | ( | signed long & | ) |
| QTextStream & QTextStream::operator>> | ( | signed int & | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a signed int i from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream& QTextStream::operator>> | ( | float & | ) |
| QTextStream& QTextStream::operator>> | ( | signed short & | ) |
| QTextStream & QTextStream::operator>> | ( | unsigned int & | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads an unsigned int i from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream & QTextStream::operator>> | ( | signed long & | i | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Reads a signed long int i from the stream and returns a reference to the stream. See flags() for an explanation of the expected input format.
| QTextStream& QTextStream::operator>> | ( | QChar & | ) |
| QTextStream& QTextStream::operator>> | ( | char & | ) |
| int QTextStream::precision | ( | ) | const [inline] |
Returns the precision. The default value is 6.
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Sets the precision to p. Returns the previous precision setting.
| int QTextStream::precision | ( | ) | const |
| QString QTextStream::read | ( | ) |
Reads the entire stream from the current position, and returns a string containing the text.
| QString QTextStream::read | ( | ) |
| QString QTextStream::readLine | ( | ) |
| QString QTextStream::readLine | ( | ) |
Reads a line from the stream and returns a string containing the text.
The returned string does not contain any trailing newline or carriage return. Note that this is different from QIODevice::readLine(), which does not strip the newline at the end of the line.
On EOF you will get a QString that is null. On reading an empty line the returned QString is empty but not null.
| QTextStream & QTextStream::readRawBytes | ( | char * | s, |
| uint | len | ||
| ) |
Reads len bytes from the stream into s and returns a reference to the stream.
The buffer s must be preallocated.
Note that no encoding is done by this function.
| QTextStream& QTextStream::readRawBytes | ( | char * | , |
| uint | len | ||
| ) |
| void QTextStream::reset | ( | void | ) |
Resets the text stream.
All flags are set to 0. The field width is set to 0. The fill character is set to ' ' (Space). The precision is set to 6.
| void QTextStream::reset | ( | ) |
| void QTextStream::setCodec | ( | QTextCodec * | codec | ) |
Sets the codec for this stream to codec. Will not try to autodetect Unicode.
Note that this function should be called before any data is read to/written from the stream.
| void QTextStream::setCodec | ( | QTextCodec * | ) |
| void QTextStream::setDevice | ( | QIODevice * | ) |
| void QTextStream::setDevice | ( | QIODevice * | iod | ) |
Sets the IO device to iod.
| void QTextStream::setEncoding | ( | Encoding | e | ) |
Sets the encoding of this stream to e, where e is one of the following values: Encoding Meaning Locale Uses local file format (Latin1 if locale is not set), but autodetecting Unicode(utf16) on input. Unicode Uses Unicode(utf16) for input and output. Output will be written in the order most efficient for the current platform (i.e. the order used internally in QString). UnicodeUTF8 Using Unicode(utf8) for input and output. If you use it for input it will autodetect utf16 and use it instead of utf8. Latin1 ISO-8859-1. Will not autodetect utf16. UnicodeNetworkOrder Uses network order Unicode(utf16) for input and output. Useful when reading Unicode data that does not start with the byte order marker. UnicodeReverse Uses reverse network order Unicode(utf16) for input and output. Useful when reading Unicode data that does not start with the byte order marker or when writing data that should be read by buggy Windows applications. RawUnicode Like Unicode, but does not write the byte order marker nor does it auto-detect the byte order. Useful only when writing to non-persistent storage used by a single process.
Locale and all Unicode encodings, except RawUnicode, will look at the first two bytes in an input stream to determine the byte order. The initial byte order marker will be stripped off before data is read.
Note that this function should be called before any data is read to or written from the stream.
| void QTextStream::setEncoding | ( | Encoding | ) |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Sets the stream flag bits bits with a bit mask mask. Returns the previous stream flags.
Equivalent to {flags( (flags() & ~mask) | (bits & mask) )}.
| void QTextStream::skipWhiteSpace | ( | ) |
Positions the read pointer at the first non-whitespace character.
| void QTextStream::skipWhiteSpace | ( | ) |
| void QTextStream::unsetDevice | ( | ) |
Unsets the IO device. Equivalent to setDevice( 0 ).
| void QTextStream::unsetDevice | ( | ) |
| int QTextStream::width | ( | ) | const |
| int QTextStream::width | ( | ) | const [inline] |
Returns the field width. The default value is 0.
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Sets the field width to w. Returns the previous field width.
| QTextStream& QTextStream::writeRawBytes | ( | const char * | , |
| uint | len | ||
| ) |
| QTextStream & QTextStream::writeRawBytes | ( | const char * | s, |
| uint | len | ||
| ) |
Writes the len bytes from s to the stream and returns a reference to the stream.
Note that no encoding is done by this function.
static const int QTextStream::adjustfield [static] |
static const int QTextStream::basefield = I_BASE_MASK [static] |
static const int QTextStream::floatfield [static] |
1.7.4
