QMediaDevices 類

QMediaDevices 類提供可用多媒體輸入和輸齣設備的有關信息。 更多...

頭：	#include <QMediaDevices>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Multimedia) target_link_libraries(mytarget PRIVATE Qt6::Multimedia)
qmake:	QT += multimedia
在 QML：	MediaDevices
繼承：	QObject

• 所有成員列錶，包括繼承成員

特性

audioInputs : const QList<QAudioDevice> audioOutputs : const QList<QAudioDevice> defaultAudioInput : const QAudioDevice

defaultAudioOutput : const QAudioDevice defaultVideoInput : const QCameraDevice videoInputs : const QList<QCameraDevice>

信號

void	audioInputsChanged ()
void	audioOutputsChanged ()
void	videoInputsChanged ()

靜態公共成員

QList<QAudioDevice>	audioInputs ()
QList<QAudioDevice>	audioOutputs ()
QAudioDevice	defaultAudioInput ()
QAudioDevice	defaultAudioOutput ()
QCameraDevice	defaultVideoInput ()
QList<QCameraDevice>	videoInputs ()

詳細描述

The QMediaDevices class provides information about the available multimedia devices and the system defaults. It monitors the following three groups:

• Audio input devices (Microphones)
• Audio output devices (Speakers, Headsets)
• Video input devices (Cameras)

QMediaDevices provides a separate list for each device group. If it detects that a new device has been connected to the system or an attached device has been disconnected from the system, it will update the corresponding device list and emit a signal notifying about the change.

The QMediaDevices::audioInputs and QMediaDevices::audioOutputs functions can be used to enumerate all microphones and speakers/headsets on the system. This example first gets a list of all connected microphones, and then prints their identifier, description, and if it is the default device or not.

const QList<QAudioDevice> audioDevices = QMediaDevices::audioInputs();
for (const QAudioDevice &device : audioDevices)
{
    out << "ID: " << device.id() << Qt::endl;
    out << "Description: " << device.description() << Qt::endl;
    out << "Is default: " << (device.isDefault() ? "Yes" : "No") << Qt::endl;
}
					

同樣， QMediaDevices::videoInputs will return a list of all connected cameras. In this example we list all connected cameras and their identifier, description, and if it is the default camera or not.

const QList<QCameraDevice> videoDevices = QMediaDevices::videoInputs();
for (const QCameraDevice &device : videoDevices)
{
    out << "ID: " << device.id() << Qt::endl;
    out << "Description: " << device.description() << Qt::endl;
    out << "Is default: " << (device.isDefault() ? "Yes" : "No") << Qt::endl;
}
					

QMediaDevices monitors the system defaults for each device group. It will notify about any changes done through the system settings. For example, if the user selects a new default audio output in the system settings, QMediaDevices will update the default audio output accordingly and emit a signal. If the system does not provide a default for a camera or an audio input, QMediaDevices will select the first device from the list as the default device.

While using the default input and output devices is often sufficient for playing back or recording multimedia, there is often a need to explicitly select the device to be used.

QMediaDevices is a singleton object and all getters are thread-safe.

特性文檔編製

[read-only] audioInputs : const QList < QAudioDevice >

Returns a list of available audio input devices on the system.

Those devices are usually microphones. Devices can be either built-in, or connected through for example USB or Bluetooth.

訪問函數：

QList<QAudioDevice>

audioInputs ()

通知程序信號：

void	audioInputsChanged ()

[read-only] audioOutputs : const QList < QAudioDevice >

Returns a list of available audio output devices on the system.

Those devices are usually loudspeakers or head sets. Devices can be either built-in, or connected through for example USB or Bluetooth.

訪問函數：

QList<QAudioDevice>

audioOutputs ()

通知程序信號：

void	audioOutputsChanged ()

[read-only] defaultAudioInput : const QAudioDevice

Returns the default audio input device.

The default device can change during the runtime of the application. The audioInputsChanged () signal is emitted in this case.

訪問函數：

QAudioDevice

defaultAudioInput ()

通知程序信號：

void	audioInputsChanged ()

[read-only] defaultAudioOutput : const QAudioDevice

Returns the default audio output device.

The default device can change during the runtime of the application. The audioOutputsChanged () signal is emitted in this case.

訪問函數：

QAudioDevice

defaultAudioOutput ()

通知程序信號：

void	audioOutputsChanged ()

[read-only] defaultVideoInput : const QCameraDevice

Returns the default camera on the system.

注意： The returned object should be checked using isNull() before being used, in case there is no default camera or no cameras at all.

The default device can change during the runtime of the application. The videoInputsChanged () signal is emitted in that case.

訪問函數：

QCameraDevice

defaultVideoInput ()

通知程序信號：

void	videoInputsChanged ()

另請參閱 videoInputs ().

[read-only] videoInputs : const QList < QCameraDevice >

Returns a list of available cameras on the system.

訪問函數：

QList<QCameraDevice>

videoInputs ()

通知程序信號：

void	videoInputsChanged ()

內容

1. 特性

2. 信號

3. 靜態公共成員

4. 詳細描述