Qt debug information files что это

02.01.202407.09.2023 admin 0 Comments

Qt Documentation

The QDebug class provides an output stream for debugging information. More.

Public Types

Public Functions

QDebug(const QDebug &o)
QDebug(QtMsgType t)
QDebug(QString *string)
QDebug(QIODevice *device)
QDebug &	operator=(const QDebug &other)
QDebug()
bool	autoInsertSpaces() const
QDebug &	maybeQuote(char c = ‘»‘)
QDebug &	maybeSpace()
QDebug &	noquote()
QDebug &	nospace()
QDebug &	quote()
QDebug &	resetFormat()
void	setAutoInsertSpaces(bool b)
void	setVerbosity(int verbosityLevel)
QDebug &	space()
void	swap(QDebug &other)
QDebug &	verbosity(int verbosityLevel)
int	verbosity() const
QDebug &	*operator &flags)*
QDebug	*operator &list)*
QDebug	*operator &vec)*
QDebug	*operator &vec)*
QDebug	*operator &vec)*
QDebug	*operator &map)*
QDebug	*operator &map)*
QDebug	*operator &map)*
QDebug	*operator &hash)*
QDebug	*operator &pair)*
QDebug	*operator &set)*

Detailed Description

QDebug is used whenever the developer needs to write out debugging or tracing information to a device, file, string or console.

Basic Use

In the common case, it is useful to call the qDebug() function to obtain a default QDebug object to use for writing debugging information.

This constructs a QDebug object using the constructor that accepts a QtMsgType value of QtDebugMsg. Similarly, the qWarning(), qCritical() and qFatal() functions also return QDebug objects for the corresponding message types.

The class also provides several constructors for other situations, including a constructor that accepts a QFile or any other QIODevice subclass that is used to write debugging information to files and other devices. The constructor that accepts a QString is used to write to a string for display or serialization.

Formatting Options

QDebug formats output so that it’s easily readable. It automatically adds spaces between arguments, and adds quotes around QString, QByteArray, QChar arguments.

You can tweak these options through the space(), nospace() and quote(), noquote() methods. Furthermore, QTextStream manipulators can be piped into a QDebug stream.

QDebugStateSaver limits changes to the formatting to the current scope. resetFormat() resets the options to the default ones.

Writing Custom Types to a Stream

Many standard types can be written to QDebug objects, and Qt provides support for most Qt value types. To add support for custom types, you need to implement a streaming operator, as in the following example:

This is described in the Debugging Techniques and Creating Custom Qt Types documents.

Member Type Documentation

enum QDebug:: VerbosityLevel

This enum describes the range of verbosity levels.

Constant	Value
QDebug::MinimumVerbosity	0
QDebug::DefaultVerbosity	2
QDebug::MaximumVerbosity	7

This enum was introduced or modified in Qt 5.13.

Member Function Documentation

QDebug:: QDebug (const QDebug &o)

Constructs a copy of the other debug stream o.

QDebug:: QDebug ( QtMsgType t)

Constructs a debug stream that writes to the handler for the message type t.

QDebug:: QDebug ( QString **string*)

Constructs a debug stream that writes to the given string.

QDebug:: QDebug ( QIODevice **device*)

Constructs a debug stream that writes to the given device.

QDebug &QDebug:: operator= (const QDebug &other)

Assigns the other debug stream to this stream and returns a reference to this stream.

QDebug::

Flushes any pending data to be written and destroys the debug stream.

bool QDebug:: autoInsertSpaces () const

Returns true if this QDebug instance will automatically insert spaces between writes.

This function was introduced in Qt 5.0.

QDebug &QDebug:: maybeQuote ( char c = ‘»‘)

Writes a character c to the debug stream, depending on the current setting for automatic insertion of quotes, and returns a reference to the stream.

This function was introduced in Qt 5.4.

QDebug &QDebug:: maybeSpace ()

Writes a space character to the debug stream, depending on the current setting for automatic insertion of spaces, and returns a reference to the stream.

QDebug &QDebug:: noquote ()

Disables automatic insertion of quotation characters around QChar, QString and QByteArray contents and returns a reference to the stream.

When quoting is disabled, these types are printed without quotation characters and without escaping of non-printable characters.

This function was introduced in Qt 5.4.

QDebug &QDebug:: nospace ()

Disables automatic insertion of spaces and returns a reference to the stream.

QDebug &QDebug:: quote ()

Enables automatic insertion of quotation characters around QChar, QString and QByteArray contents and returns a reference to the stream.

Quoting is enabled by default.

This function was introduced in Qt 5.4.

QDebug &QDebug:: resetFormat ()

Resets the stream formatting options, bringing it back to its original constructed state.

This function was introduced in Qt 5.4.

void QDebug:: setAutoInsertSpaces ( bool b)

Enables automatic insertion of spaces between writes if b is true; otherwise automatic insertion of spaces is disabled.

This function was introduced in Qt 5.0.

void QDebug:: setVerbosity ( int verbosityLevel)

Sets the verbosity of the stream to verbosityLevel.

The allowed range is from 0 to 7. The default value is 2.

This function was introduced in Qt 5.6.

QDebug &QDebug:: space ()

Writes a space character to the debug stream and returns a reference to the stream.

The stream remembers that automatic insertion of spaces is enabled for future writes.

void QDebug:: swap ( QDebug &other)

Swaps this debug stream instance with other. This function is very fast and never fails.

This function was introduced in Qt 5.0.

QDebug &QDebug:: verbosity ( int verbosityLevel)

Sets the verbosity of the stream to verbosityLevel and returns a reference to the stream.

The allowed range is from 0 to 7. The default value is 2.

This function was introduced in Qt 5.13.

int QDebug:: verbosity () const

Returns the verbosity of the debug stream.

Streaming operators can check the value to decide whether verbose output is desired and print more information depending on the level. Higher values indicate that more information is desired.

The allowed range is from 0 to 7. The default value is 2.

This function was introduced in Qt 5.6.

QDebug &QDebug:: operator ( QChar t)

QDebug &QDebug:: operator ( bool t)

Writes the boolean value, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( char t)

Writes the character, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( short t)

Writes the signed short integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( unsigned short t)

Writes then unsigned short integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( char16_t t)

Writes the UTF-16 character, t, to the stream and returns a reference to the stream.

This function was introduced in Qt 5.5.

QDebug &QDebug:: operator ( char32_t t)

Writes the UTF-32 character, t, to the stream and returns a reference to the stream.

This function was introduced in Qt 5.5.

QDebug &QDebug:: operator ( int t)

Writes the signed integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( unsigned int t)

Writes then unsigned integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( long t)

Writes the signed long integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( unsigned long t)

Writes then unsigned long integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( qint64 t)

Writes the signed 64-bit integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( quint64 t)

Writes then unsigned 64-bit integer, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( float t)

Writes the 32-bit floating point number, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator ( double t)

Writes the 64-bit floating point number, t, to the stream and returns a reference to the stream.

QDebug &QDebug:: operator (const char *t)

Writes the ‘\0’-terminated string, t, to the stream and returns a reference to the stream. The string is never quoted nor transformed to the output, but note that some QDebug backends might not be 8-bit clean.

QDebug &QDebug:: operator (const QString &t)

Writes the string, t, to the stream and returns a reference to the stream. Normally, QDebug prints the string inside quotes and transforms non-printable characters to their Unicode values (\u1234).