ScreenCapture QML Type

This type is used for capturing a screen. 更多...

import 语句：	`import QtMultimedia`
Since:	Qt 6.5
在 C++：	QScreenCapture

所有成员列表，包括继承成员

特性

active : bool
error : enumeration
errorString : string
screen : Screen

详细描述

ScreenCapture captures a screen. It is managed by MediaCaptureSession where the captured screen can be displayed in a video preview object or recorded to a file.

The code below shows a simple capture session with ScreenCapture playing back the captured primary screen view in VideoOutput .

CaptureSession {
    id: captureSession
    screenCapture: ScreenCapture {
        id: screenCapture
        active: true
    }
    videoOutput: VideoOutput {
        id: videoOutput
    }
}

屏幕捕获局限性

On Qt 6.5.2 and above, the following limitations apply to using ScreenCapture:

It is only supported with the FFmpeg backend.
On Linux systems using the Wayland compositor, the screen capture implementation is experimental and comes with the following limitations. Due to restrictions of the Wayland protocol, it's impossible to set and get the target screen via the API of the QScreenCapture class. Instead, the OS will show a screen selection wizard upon invoking QScreenCapture::setActive(true) . The screen capture feature requires the installation of the ScreenCast service supported via XDG Desktop Portal and {https://pipewire.org/}{PipeWire} (0.3). These limitations might change in the future.

It is not supported on mobile operating systems, except on Android. Screen Capture on Android needs additional Android foreground service permission to be added to the AndroidManifest.xml 文件：

<manifest ...>
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PROJECTION" />
<application ...>
<service android:name="org.qtproject.qt.android.multimedia.QtScreenCaptureService"
android:foregroundServiceType="mediaProjection"
android:exported="false"/>
</service>
</application>
</manifest>

On embedded with EGLFS, it has limited functionality. For Qt Quick applications, the class is currently implemented via QQuickWindow::grabWindow , which can cause performance issues.
In most cases, we set a screen capture frame rate that equals the screen refresh rate, except on Windows, where the rate might be flexible. Such a frame rate (75/120 FPS) might cause performance issues on weak CPUs if the captured screen is of 4K resolution. On EGLFS, the capture frame rate is currently locked to 30 FPS.

另请参阅 WindowCapture and CaptureSession .

特性文档编制

active : bool

Describes whether the capturing is currently active.

error : enumeration [read-only]

Returns a code of the last error.

errorString : string [read-only]

Returns a human readable string describing the cause of error.

screen : Screen

Describes the screen for capturing.