Position QML Type

The Position type holds positional data at a particular point in time, such as coordinate (longitude, latitude, altitude) and speed. 更多...

import 语句: import QtPositioning 5.2
Since: Qt 5.2

特性

详细描述

The Position type holds values related to geographic location such as a coordinate (longitude, latitude, and altitude), the timestamp when the Position was obtained, the speed at that time, and the accuracy of the data.

Primarily, it is used in the position property of a PositionSource , as the basic unit of data available from the system location data source.

Not all properties of a Position object are necessarily valid or available (for example latitude and longitude may be valid, but speed update has not been received or set manually). As a result, corresponding "valid" properties are available (for example coordinate and longitudeValid , latitudeValid etc) to discern whether the data is available and valid in this position update.

Position objects are read-only and can only be produced by a PositionSource .

用法范例

See the example given for the PositionSource type, or the GeoFlickr example application.

另请参阅 PositionSource and coordinate .

特性文档编制

altitudeValid : bool

This property is true if coordinate's altitude has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

另请参阅 coordinate .

coordinate : coordinate

This property holds the latitude, longitude, and altitude value of the Position.

It is a read-only property.

另请参阅 longitudeValid , latitudeValid ,和 altitudeValid .

direction : double

This property holds the value of the direction of travel in degrees from true north.

It is a read-only property.

This QML property was introduced in Qt Positioning 5.3.

另请参阅 directionValid .

directionValid : bool

This property is true if direction has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

This QML property was introduced in Qt Positioning 5.3.

另请参阅 direction .

horizontalAccuracy : real

This property holds the horizontal accuracy of the coordinate (in meters).

另请参阅 horizontalAccuracyValid and coordinate .

horizontalAccuracyValid : bool

This property is true if horizontalAccuracy has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

另请参阅 horizontalAccuracy .

latitudeValid : bool

This property is true if coordinate's latitude has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

另请参阅 coordinate .

longitudeValid : bool

This property is true if coordinate's longitude has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

另请参阅 coordinate .

magneticVariation : double

This property holds the angle between the horizontal component of the magnetic field and true north, in degrees. Also known as magnetic declination. A positive value indicates a clockwise direction from true north and a negative value indicates a counter-clockwise direction.

It is a read-only property.

This QML property was introduced in Qt Positioning 5.4.

另请参阅 magneticVariationValid .

magneticVariationValid : bool

This property is true if magneticVariation has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

This QML property was introduced in Qt Positioning 5.4.

另请参阅 magneticVariation .

speed : double

This property holds the value of speed (groundspeed, meters / second).

It is a read-only property.

另请参阅 speedValid and coordinate .

speedValid : bool

This property is true if speed has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

另请参阅 speed .

timestamp : date

This property holds the timestamp when this position was received. If the property has not been set, it is invalid.

It is a read-only property.

verticalAccuracy : real

This property holds the vertical accuracy of the coordinate (in meters).

另请参阅 verticalAccuracyValid and coordinate .

verticalAccuracyValid : bool

This property is true if verticalAccuracy has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

另请参阅 verticalAccuracy .

verticalSpeed : double

This property holds the value of the vertical speed in meters per second.

It is a read-only property.

This QML property was introduced in Qt Positioning 5.3.

另请参阅 verticalSpeedValid .

verticalSpeedValid : bool

This property is true if verticalSpeed has been set (to indicate whether that data has been received or not, as every update does not necessarily contain all data).

This QML property was introduced in Qt Positioning 5.3.

另请参阅 verticalSpeed .