QIRProximityReading Class
The QIRProximityReading class holds readings from the IR proximity sensor. 更多...
| 头文件: | #include <QIRProximityReading> |
| qmake: | QT += sensors |
| 开始支持版本: | Qt 5.1 |
| 基类: | QSensorReading |
属性
- reflectance : const qreal
- 1 个属性继承自 QSensorReading
- 1 个属性继承自 QObject
公有函数
| qreal | reflectance() const |
| void | setReflectance(qreal reflectance) |
- 4 个公有函数继承自 QSensorReading
- 32 个公有函数继承自 QObject
其他继承的成员
- 1 个公有槽函数继承自 QObject
- 2 个信号继承自 QObject
- 1 个公有变量继承自 QObject
- 10 个静态公有成员继承自 QObject
- 9 个受保护的函数继承自 QObject
- 2 个受保护的变量继承自 QObject
详细描述
The QIRProximityReading class holds readings from the IR proximity sensor.
The IR (infra-red) proximity sensor detects proximity by beaming out infra-red light and detecting how much of the light returns.
The biggest limitation of this technology is that there is no reliable way to turn the reflectance values into distances unless both the item being detected and the ambient conditions are known.
QIRProximityReading Units
The sensor reports reflectance as a decimal fraction in the range of 0 - 1. That is, 0 indicates nothing was detected within the range of the sensor and 1 indicates the infra-red signal returned at the full power level that it was sent at.
With some IR sensors, it is quite uncommon to reach the top and the bottom of the value range, and some parts of the range ends might not be obtainable at all. This is due to the behavior of the sensor hardware. With these sensors, the absolute value of reflectance should never be used directly. Instead, applications should react to the relative change of the reading values. Use QProximitySensor if it is only necessary to check if something is close to the device or not.
属性
reflectance : const qreal
Holds the reflectance value.
The reflectance is a decimal fraction (from 0 to 1) indicating how much of the transmitted infra-red light was returned.
访问函数:
| qreal | reflectance() const |
成员函数
void QIRProximityReading::setReflectance(qreal reflectance)
Sets the reflectance value to reflectance.
参见 reflectance().