The QAccelerometer class is a convenience wrapper around QSensor . 更多...
| 頭： | #include <QAccelerometer> |
| qmake: | QT += sensors |
| Since: | Qt 5.1 |
| 繼承： | QSensor |
| enum | AccelerationMode { Combined, Gravity, User } |
| QAccelerometer (QObject * parent = Q_NULLPTR) | |
| virtual | ~QAccelerometer () |
| AccelerationMode | accelerationMode () const |
| QAccelerometerReading * | reading () const |
| void | setAccelerationMode (AccelerationMode accelerationMode ) |
| void | accelerationModeChanged (AccelerationMode accelerationMode ) |
The QAccelerometer class is a convenience wrapper around QSensor .
唯一行為差異是此類正確設置類型。
It also supports changing the acceleration mode, which controls whether the force of gravity is included in the accelerometer values or not.
Furthermore, this class features a reading () 函數返迴 QAccelerometerReading 而不是 QSensorReading .
有關傳感器如何工作的細節，見 QAccelerometerReading .
另請參閱 QAccelerometerReading .
This enum represents the acceleration mode of an acceleration sensor.
The acceleration mode controls how the sensor reports acceleration. QAccelerometer::Combined is the only mode in which the values can be directly physically measured, the others are an approximation.
| 常量 | 值 | 描述 |
|---|---|---|
QAccelerometer::Combined
|
0
|
Both the acceleration caused by gravity and the acceleration caused by the user moving the device is reported combined. |
QAccelerometer::Gravity
|
1
|
Only the acceleration caused by gravity is reported. Movements of the device caused by the user have no effect other than changing the direction when the device is rotated. |
QAccelerometer::User
|
2
|
Only the acceleration caused by the user moving the device is reported, the effect of gravity is canceled out. A device at rest therefore should report values of, or close to, zero. In other APIs, this mode might be known as linear acceleration . |
該枚舉在 Qt 5.1 引入或被修改。
另請參閱 QAccelerometer::accelerationMode .
This property holds the acceleration mode controls how acceleration values are reported.
The acceleration mode controls how the acceleration sensor reports its values. The default mode is QAccelerometer::Combined , which means the acceleration caused by gravity is included in the reported values.
Acceleration caused by gravity and acceleration caused by the user moving the device are physically impossible to distinguish because of general relativity. Most devices use sensor fusion to figure out which parts of the acceleration is caused by gravity, for example by using a rotation sensor to calculate the gravity direction and assuming a fixed magnitude for gravity. Therefore the result is only an approximation and may be inaccurate. The QAccelerometer::Combined mode is the most accurate one, as it does not involve approximating the gravity.
Not all backends and devices might support setting the acceleration mode. For those cases, the default mode QAccelerometer::Combined is used, changing it has no effect.
該特性在 Qt 5.1 引入。
訪問函數：
| AccelerationMode | accelerationMode () const |
| void | setAccelerationMode (AccelerationMode accelerationMode ) |
通知程序信號：
| void | accelerationModeChanged (AccelerationMode accelerationMode ) |
構造傳感器作為子級對於 parent .
[虛擬]
QAccelerometer::
~QAccelerometer
()
銷毀傳感器。停止傳感器若尚未停止。
[signal]
void
QAccelerometer::
accelerationModeChanged
(
AccelerationMode
accelerationMode
)
Emitted when the accelerationMode was changed.
該函數在 Qt 5.1 引入。
注意： 通知程序信號對於特性 accelerationMode .
返迴用於此傳感器的讀取類。
另請參閱 QSensor::reading ().
Sets the acceleration mode to accelerationMode .
該函數在 Qt 5.1 引入。
注意： setter 函數對於特性 accelerationMode .
另請參閱 accelerationMode ().