QCameraViewfinderSettings 类

QCameraViewfinderSettings 类提供一套取景器设置。更多...

头：	#include <QCameraViewfinderSettings>
qmake:	QT += multimedia
Since:	Qt 5.5

该类在 Qt 5.5 引入。

所有成员列表，包括继承成员

公共函数

	QCameraViewfinderSettings (const QCameraViewfinderSettings & other )
	QCameraViewfinderSettings ()
QCameraViewfinderSettings &	operator= (QCameraViewfinderSettings && other )
QCameraViewfinderSettings &	operator= (const QCameraViewfinderSettings & other )
	~QCameraViewfinderSettings ()
bool	isNull () const
qreal	maximumFrameRate () const
qreal	minimumFrameRate () const
QSize	pixelAspectRatio () const
QVideoFrame::PixelFormat	pixelFormat () const
QSize	resolution () const
void	setMaximumFrameRate (qreal rate )
void	setMinimumFrameRate (qreal rate )
void	setPixelAspectRatio (const QSize & ratio )
void	setPixelAspectRatio (int horizontal , int vertical )
void	setPixelFormat (QVideoFrame::PixelFormat format )
void	setResolution (const QSize & resolution )
void	setResolution (int width , int height )
void	swap (QCameraViewfinderSettings & other )

bool	operator!= (const QCameraViewfinderSettings & lhs , const QCameraViewfinderSettings & rhs )
bool	operator== (const QCameraViewfinderSettings & lhs , const QCameraViewfinderSettings & rhs )

详细描述

A viewfinder settings object is used to specify the viewfinder settings used by QCamera . Viewfinder settings are selected by constructing a QCameraViewfinderSettings object, setting the desired properties and then passing it to a QCamera instance using the QCamera::setViewfinderSettings () 函数。

QCameraViewfinderSettings viewfinderSettings;
viewfinderSettings.setResolution(640, 480);
viewfinderSettings.setMinimumFrameRate(15.0);
viewfinderSettings.setMaximumFrameRate(30.0);
camera->setViewfinderSettings(viewfinderSettings);

Different cameras may have different capabilities. The application should query the camera capabilities before setting parameters. For example, the application should call QCamera::supportedViewfinderResolutions () 先于调用 setResolution ().

另请参阅 QCamera .

成员函数文档编制

QCameraViewfinderSettings:: QCameraViewfinderSettings (const QCameraViewfinderSettings & other )

Constructs a copy of the viewfinder settings object other .

QCameraViewfinderSettings:: QCameraViewfinderSettings ()

Constructs a null viewfinder settings object.

QCameraViewfinderSettings &QCameraViewfinderSettings:: operator= ( QCameraViewfinderSettings && other )

移动 other to this viewfinder settings object and returns a reference to this object.

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

Assigns the value of other to a viewfinder settings object.

QCameraViewfinderSettings:: ~QCameraViewfinderSettings ()

Destroys a viewfinder settings object.

bool QCameraViewfinderSettings:: isNull () const

Identifies if a viewfinder settings object is uninitalized.

Returns true if the settings are null, and false if they are not.

qreal QCameraViewfinderSettings:: maximumFrameRate () const

Returns the viewfinder maximum frame rate in frames per second.

另请参阅 setMaximumFrameRate () 和 minimumFrameRate ().

qreal QCameraViewfinderSettings:: minimumFrameRate () const

Returns the viewfinder minimum frame rate in frames per second.

另请参阅 setMinimumFrameRate () 和 maximumFrameRate ().

QSize QCameraViewfinderSettings:: pixelAspectRatio () const

Returns the viewfinder pixel aspect ratio.

另请参阅 setPixelAspectRatio ().

QVideoFrame::PixelFormat QCameraViewfinderSettings:: pixelFormat () const

Returns the viewfinder pixel format.

另请参阅 setPixelFormat ().

QSize QCameraViewfinderSettings:: resolution () const

Returns the viewfinder resolution.

另请参阅 setResolution ().

void QCameraViewfinderSettings:: setMaximumFrameRate ( qreal rate )

Sets the viewfinder maximum frame rate in frames per second.

If the maximum frame rate is equal to the minimum frame rate, the frame rate is fixed. If not, the actual frame rate fluctuates between the minimum and the maximum.

若给定 rate equals to 0 , the backend makes an optimal choice based on the supported frame rates and the other viewfinder settings.

另请参阅 maximumFrameRate (), setMinimumFrameRate ()，和 QCamera::supportedViewfinderFrameRateRanges ().

void QCameraViewfinderSettings:: setMinimumFrameRate ( qreal rate )

Sets the viewfinder minimum frame rate in frames per second.

If the minimum frame rate is equal to the maximum frame rate, the frame rate is fixed. If not, the actual frame rate fluctuates between the minimum and the maximum.

若给定 rate equals to 0 , the backend makes an optimal choice based on the supported frame rates and the other viewfinder settings.

另请参阅 minimumFrameRate (), setMaximumFrameRate ()，和 QCamera::supportedViewfinderFrameRateRanges ().

void QCameraViewfinderSettings:: setPixelAspectRatio (const QSize & ratio )

Sets the viewfinder pixel aspect ratio .

另请参阅 pixelAspectRatio ().

void QCameraViewfinderSettings:: setPixelAspectRatio ( int horizontal , int vertical )

这是重载函数。

设置 horizontal and vertical elements of the viewfinder's pixel aspect ratio.

void QCameraViewfinderSettings:: setPixelFormat ( QVideoFrame::PixelFormat format )

Sets the viewfinder pixel format .

若给定 format 等于 QVideoFrame::Format_Invalid , the backend uses the default format.

另请参阅 pixelFormat () 和 QCamera::supportedViewfinderPixelFormats ().

void QCameraViewfinderSettings:: setResolution (const QSize & resolution )

Sets the viewfinder resolution .

若给定 resolution is empty, the backend makes an optimal choice based on the supported resolutions and the other viewfinder settings.

If the camera is used to capture videos or images, the viewfinder resolution might be ignored if it conflicts with the capture resolution.

另请参阅 resolution (), QVideoEncoderSettings::setResolution (), QImageEncoderSettings::setResolution ()，和 QCamera::supportedViewfinderResolutions ().

void QCameraViewfinderSettings:: setResolution ( int width , int height )