内容

• 特性
• 公共函数
• 重实现公共函数
• 静态公共成员
• 详细描述
• QMagnetometerReading Units
• Calibration

QMagnetometerReading Class

The QMagnetometerReading class represents one reading from the magnetometer. 更多...

头：	#include <QMagnetometerReading>
qmake:	QT += sensors
Since:	Qt 5.1
继承：	QSensorReading

• 所有成员列表，包括继承成员
• 过时成员

特性

• calibrationLevel : const qreal
• x : const qreal
• y : const qreal
• z : const qreal

• 1 特性继承自 QSensorReading
• 1 特性继承自 QObject

公共函数

	QMagnetometerReading (QObject * parent = DECLARE_READING(QMagnetometerReading))
virtual	~QMagnetometerReading ()
qreal	calibrationLevel () const
void	setCalibrationLevel (qreal calibrationLevel )
void	setX (qreal x )
void	setY (qreal y )
void	setZ (qreal z )
qreal	x () const
qreal	y () const
qreal	z () const

重实现公共函数

virtual void

copyValuesFrom (QSensorReading * other ) override

• 4 公共函数继承自 QSensorReading
• 31 公共函数继承自 QObject

静态公共成员

const QMetaObject

staticMetaObject

• 9 静态公共成员继承自 QObject

额外继承成员

• 1 公共槽继承自 QObject
• 2 信号继承自 QObject
• 9 保护函数继承自 QObject

详细描述

The QMagnetometerReading class represents one reading from the magnetometer.

QMagnetometerReading Units

The magnetometer returns magnetic flux density values along 3 axes. The scale of the values is teslas. The axes are arranged as follows.

The magnetometer can report on either raw magnetic flux values or geomagnetic flux values. By default it returns raw magnetic flux values. The QMagnetometer::returnGeoValues property must be set to return geomagnetic flux values.

The primary difference between raw and geomagnetic values is that extra processing is done to eliminate local magnetic interference from the geomagnetic values so they represent only the effect of the Earth's magnetic field. This process is not perfect and the accuracy of each reading may change.

The image below shows the difference between geomagnetic (on the left) and raw (on the right) readings for a phone that is being subjected to magnetic interference.

The accuracy of each reading is measured as a number from 0 to 1. A value of 1 is the highest level that the device can support and 0 is the worst.

Calibration

If the device is reporting low accuracy, then calibration might be needed before acceptable measurements can be provided. Basic calibration can usually be done by either rotating your device in a figure of eight, or by rotating the device along each of its three axes. For more information, check your device's documentation on how to calibrate the magnetic sensor.

特性文档编制

calibrationLevel : const qreal

This property holds the accuracy of the reading.

度量值从 0 到 1，更高值更佳。

Note that this only changes when measuring geomagnetic flux density. Raw magnetic flux readings will always have a value of 1.

访问函数：

qreal

calibrationLevel () const

另请参阅 QMagnetometerReading Units and Calibration .

x : const qreal

This property holds the raw magnetic flux density on the X axis.

Measured as teslas.

访问函数：

qreal

x () const

另请参阅 QMagnetometerReading Units .

y : const qreal

This property holds the raw magnetic flux density on the Y axis.

Measured as teslas.

访问函数：

qreal

y () const

另请参阅 QMagnetometerReading Units .

z : const qreal

This property holds the raw magnetic flux density on the Z axis.

Measured as teslas.

访问函数：

qreal

z () const

另请参阅 QMagnetometerReading Units .

成员函数文档编制

QMagnetometerReading:: QMagnetometerReading ( QObject * parent = DECLARE_READING(QMagnetometerReading))

Default constructs an instance of QMagnetometerReading.

[虚拟] QMagnetometerReading:: ~QMagnetometerReading ()

Destroys the instance of QMagnetometerReading. The destructor is virtual.

[override virtual] void QMagnetometerReading:: copyValuesFrom ( QSensorReading * other )

void QMagnetometerReading:: setCalibrationLevel ( qreal calibrationLevel )

Sets the accuracy of the reading to calibrationLevel .

另请参阅 calibrationLevel ().

void QMagnetometerReading:: setX ( qreal x )

Sets the raw magnetic flux density on the X axis to x .

另请参阅 x ().

void QMagnetometerReading:: setY ( qreal y )

Sets the raw magnetic flux density on the Y axis to y .

另请参阅 y ().

void QMagnetometerReading:: setZ ( qreal z )

Sets the raw magnetic flux density on the Z axis to z .

另请参阅 z ().