QQuickWindow ¶

函数 ¶

槽 ¶

信号 ¶

静态函数 ¶

渲染 ¶

QQuickWindow uses a scene graph to represent what needs to be rendered. This scene graph is disconnected from the QML scene and potentially lives in another thread, depending on the platform implementation. Since the rendering scene graph lives independently from the QML scene, it can also be completely released without affecting the state of the QML scene.

sceneGraphInitialized() signal is emitted on the rendering thread before the QML scene is rendered to the screen for the first time. If the rendering scene graph has been released, the signal will be emitted again before the next frame is rendered.

Integration with OpenGL ¶

When using the default OpenGL adaptation, it is possible to integrate OpenGL calls directly into the QQuickWindow using the same OpenGL context as the Qt Quick Scene Graph. This is done by connecting to the beforeRendering() or afterRendering() 信号。

注意

当使用 beforeRendering() , make sure to disable clearing before rendering with setClearBeforeRendering() .

Exposure and Visibility ¶

当 QQuickWindow instance is deliberately hidden with hide() or setVisible (false), it will stop rendering and its scene graph and graphics context might be released. The sceneGraphInvalidated() signal will be emitted when this happens.

警告

It is crucial that graphics operations and interaction with the scene graph happens exclusively on the rendering thread, primarily during the updatePaintNode() phase.

警告

As signals related to rendering might be emitted from the rendering thread, connections should be made using DirectConnection .

资源管理 ¶

QML will try to cache images and scene graph nodes to improve performance, but in some low-memory scenarios it might be required to aggressively release these resources. The releaseResources() can be used to force the clean up of certain resources. Calling releaseResources() may result in the entire scene graph and in the case of the OpenGL adaptation the associated context will be deleted. The sceneGraphInvalidated() signal will be emitted when this happens.

注意

All classes with QSG prefix should be used solely on the scene graph’s rendering thread. See 场景图形和渲染 了解更多信息。

Context and Surface Formats ¶

While it is possible to specify a QSurfaceFormat for every QQuickWindow by calling the member function setFormat() , windows may also be created from QML by using the Window and ApplicationWindow elements. In this case there is no C++ code involved in the creation of the window instance, yet applications may still wish to set certain surface format values, for example to request a given OpenGL version or profile. Such applications can call the static function setDefaultFormat() at startup. The specified format will be used for all Quick windows created afterwards.

另请参阅

场景图形 - QML 下的 OpenGL

class QQuickWindow ( renderControl ) ¶

QQuickWindow([parent=None])

param parent

QWindow

param renderControl

QQuickRenderControl

Constructs a window for displaying a QML scene with parent window parent .

PySide2.QtQuick.QQuickWindow. CreateTextureOption ¶

The enums are used to customize a texture is wrapped.

常量	描述
QQuickWindow.TextureHasAlphaChannel	The texture has an alpha channel and should be drawn using blending.
QQuickWindow.TextureHasMipmaps	The texture has mipmaps and can be drawn with mipmapping enabled.
QQuickWindow.TextureOwnsGLTexture	The texture object owns the texture id and will delete the OpenGL texture when the texture object is deleted.
QQuickWindow.TextureCanUseAtlas	The image can be uploaded into a texture atlas.
QQuickWindow.TextureIsOpaque	The texture will return false for hasAlphaChannel() and will not be blended. This flag was added in Qt 5.6.

PySide2.QtQuick.QQuickWindow. RenderStage ¶

常量	描述
QQuickWindow.BeforeSynchronizingStage	Before synchronization.
QQuickWindow.AfterSynchronizingStage	After synchronization.
QQuickWindow.BeforeRenderingStage	Before rendering.
QQuickWindow.AfterRenderingStage	After rendering.
QQuickWindow.AfterSwapStage	After the frame is swapped.
QQuickWindow.NoStage	As soon as possible. This value was added in Qt 5.6.

另请参阅

场景图形和渲染

PySide2.QtQuick.QQuickWindow. SceneGraphError ¶

This enum describes the error in a sceneGraphError() 信号。

常量	描述
QQuickWindow.ContextNotAvailable	graphics context creation failed. This typically means that no suitable OpenGL implementation was found, for example because no graphics drivers are installed and so no OpenGL 2 support is present. On mobile and embedded boards that use OpenGL ES such an error is likely to indicate issues in the windowing system integration and possibly an incorrect configuration of Qt.

PySide2.QtQuick.QQuickWindow. TextRenderType ¶

This enum describes the default render type of text-like elements in Qt Quick ( 文本 , TextInput , etc.).

Select if you prefer text to look native on the target platform and do not require advanced features such as transformation of the text. Using such features in combination with the render type will lend poor and sometimes pixelated results.

常量	描述
QQuickWindow.QtTextRendering	Use Qt’s own rasterization algorithm.
QQuickWindow.NativeTextRendering	Use the operating system’s native rasterizer for text.

PySide2.QtQuick.QQuickWindow. NativeObjectType ¶

Specifies the type of the native object passed to functions such as createTextureFromNativeObject() .

常量	描述
QQuickWindow.NativeObjectTexture	The native object is a 2D texture (OpenGL, Direct3D 11, Metal) or image (Vulkan).

PySide2.QtQuick.QQuickWindow. activeFocusItem ( ) ¶

返回类型

QQuickItem

PySide2.QtQuick.QQuickWindow. activeFocusItemChanged ( ) ¶

PySide2.QtQuick.QQuickWindow. afterAnimating ( ) ¶

PySide2.QtQuick.QQuickWindow. afterRenderPassRecording ( ) ¶

PySide2.QtQuick.QQuickWindow. afterRendering ( ) ¶

PySide2.QtQuick.QQuickWindow. afterSynchronizing ( ) ¶

PySide2.QtQuick.QQuickWindow. beforeRenderPassRecording ( ) ¶

PySide2.QtQuick.QQuickWindow. beforeRendering ( ) ¶

PySide2.QtQuick.QQuickWindow. beforeSynchronizing ( ) ¶

PySide2.QtQuick.QQuickWindow. beginExternalCommands ( ) ¶

When mixing raw graphics (OpenGL, Vulkan, Metal, etc.) commands with scene graph rendering, it is necessary to call this function before recording commands to the command buffer used by the scene graph to render its main render pass. This is to avoid clobbering state.

In practice this function is often called from a slot connected to the beforeRenderPassRecording() or afterRenderPassRecording() signals.

The function does not need to be called when recording commands to the application’s own command buffer (such as, a VkCommandBuffer or MTLCommandBuffer + MTLRenderCommandEncoder created and managed by the application, not retrieved from the scene graph). With graphics APIs where no native command buffer concept is exposed (OpenGL, Direct 3D 11), and endExternalCommands() together provide a replacement for resetOpenGLState() .

Calling this function and endExternalCommands() is not necessary within the render() implementation of a QSGRenderNode because the scene graph performs the necessary steps implicitly for render nodes.

Native graphics objects (such as, graphics device, command buffer or encoder) are accessible via getResource() .

警告

Watch out for the fact that CommandListResource may return a different object between - endExternalCommands() . This can happen when the underlying implementation provides a dedicated secondary command buffer for recording external graphics commands within a render pass. Therefore, always query CommandListResource after calling this function. Do not attempt to reuse an object from an earlier query.

注意

This function has no effect when the scene graph is using OpenGL directly and the RHI graphics abstraction layer is not in use. Refer to resetOpenGLState() in that case.

注意

When the scenegraph is using the RHI graphics abstraction layer with the OpenGL backend underneath, pay attention to the fact that the OpenGL state in the context can have arbitrary settings, and this function does not perform any resetting of the state back to defaults. Call resetOpenGLState() if that is seen necessary.

另请参阅

endExternalCommands() resetOpenGLState()

PySide2.QtQuick.QQuickWindow. clearBeforeRendering ( ) ¶

返回类型

bool

Returns whether clearing of the color buffer is done before rendering or not.

另请参阅

setClearBeforeRendering()

PySide2.QtQuick.QQuickWindow. color ( ) ¶

返回类型

QColor

另请参阅

setColor()

PySide2.QtQuick.QQuickWindow. colorChanged ( arg__1 ) ¶

参数

arg__1 – QColor

PySide2.QtQuick.QQuickWindow. contentItem ( ) ¶

返回类型

QQuickItem

PySide2.QtQuick.QQuickWindow. createTextureFromId ( id , size [ , options=QQuickWindow.CreateTextureOption() ] ) ¶

参数

• id – uint

• size – QSize

• options – CreateTextureOptions

返回类型

QSGTexture

注意

此函数被弃用。

创建新 QSGTexture object from an existing OpenGL texture id and size .

The caller of the function is responsible for deleting the returned texture.

The returned texture will be using GL_TEXTURE_2D as texture target and assumes that internal format is GL_RGBA . Reimplement QSGTexture to create textures with different parameters.

使用 options to customize the texture attributes. The TextureUsesAtlas option is ignored.

警告

This function will return null if the scenegraph has not yet been initialized or OpenGL is not in use.

注意

This function only has an effect when using the default OpenGL scene graph adaptation.

注意

This function has no effect when running on the RHI graphics abstraction. Use createTextureFromNativeObject() 代替。

另请参阅

sceneGraphInitialized() QSGTexture

PySide2.QtQuick.QQuickWindow. createTextureFromImage ( image ) ¶

参数

image – QImage

返回类型

QSGTexture

这是重载函数。

PySide2.QtQuick.QQuickWindow. createTextureFromImage ( image , options ) ¶

参数

• image – QImage

• options – CreateTextureOptions

返回类型

QSGTexture

创建新 QSGTexture from the supplied image . If the image has an alpha channel, the corresponding texture will have an alpha channel.

The caller of the function is responsible for deleting the returned texture. For example whe using the OpenGL adaptation the actual OpenGL texture will be deleted when the texture object is deleted.

当 options contains TextureCanUseAtlas , the engine may put the image into a texture atlas. Textures in an atlas need to rely on normalizedTextureSubRect() for their geometry and will not support Repeat . Other values from CreateTextureOption 被忽略。

当 options contains TextureIsOpaque , the engine will create an RGB texture which returns false for hasAlphaChannel() . Opaque textures will in most cases be faster to render. When this flag is not set, the texture will have an alpha channel based on the image’s format.

当 options contains TextureHasMipmaps , the engine will create a texture which can use mipmap filtering. Mipmapped textures can not be in an atlas.

When using the OpenGL adaptation, the returned texture will be using GL_TEXTURE_2D as texture target and GL_RGBA as internal format. Reimplement QSGTexture to create textures with different parameters.

警告

This function will return 0 if the scene graph has not yet been initialized.

警告

The returned texture is not memory managed by the scene graph and must be explicitly deleted by the caller on the rendering thread. This is achieved by deleting the texture from a QSGNode destructor or by using deleteLater() in the case where the texture already has affinity to the rendering thread.

This function can be called from any thread.

另请参阅

sceneGraphInitialized() QSGTexture

PySide2.QtQuick.QQuickWindow. createTextureFromNativeObject ( type , nativeObjectPtr , nativeLayout , size [ , options=QQuickWindow.CreateTextureOption() ] ) ¶

参数

• type – NativeObjectType

• nativeObjectPtr – void

• nativeLayout – int

• size – QSize

• options – CreateTextureOptions

返回类型

QSGTexture

创建新 QSGTexture object from an existing native object.

本机对象被包裹 (但不归其所有) 通过结果 QSGTexture 。函数调用者负责删除返回的 QSGTexture ，但不会销毁底层本机对象。

type specifies the type of the object. In practice the type is NativeObjectTexture , indicating that the native object is a texture or image of the underlying graphics API. Other types may be introduced in the future.

此函数目前仅适用于 2D RGBA 纹理。

不像 createTextureFromId() , this function supports both direct OpenGL usage and the RHI abstracted rendering path.

警告

This function will return null if the scenegraph has not yet been initialized.

使用 options to customize the texture attributes. Only the TextureHasAlphaChannel and TextureHasMipmaps are taken into account here.

警告

不像 createTextureFromId() , this function never takes ownership of the native object, and the TextureOwnsGLTexture flag is ignored.

size 指定大小 (以像素为单位)。

nativeObjectPtr is a pointer to the native object handle. With OpenGL, the native handle is a GLuint value, so nativeObjectPtr is then a pointer to a GLuint. With Vulkan, the native handle is a VkImage, so nativeObjectPtr is a pointer to a VkImage. With Direct3D 11 and Metal nativeObjectPtr is a pointer to a ID3D11Texture2D or MTLTexture pointer.

注意

Pay attention to the fact that nativeObjectPtr is always a pointer to the native texture handle type, even if the native type itself is a pointer.

nativeLayout is only used for APIs like Vulkan. When applicable, it must specify the current image layout, such as, a VkImageLayout value.

另请参阅

sceneGraphInitialized() QSGTexture nativeTexture()

PySide2.QtQuick.QQuickWindow. effectiveDevicePixelRatio ( ) ¶

返回类型

qreal

Returns the device pixel ratio for this window.

This is different from devicePixelRatio() in that it supports redirected rendering via QQuickRenderControl . When using a QQuickRenderControl ， QQuickWindow is often not created, meaning it is never shown and there is no underlying native window created in the windowing system. As a result, querying properties like the device pixel ratio cannot give correct results. Use this function instead.

另请参阅

devicePixelRatio()

PySide2.QtQuick.QQuickWindow. endExternalCommands ( ) ¶

When mixing raw graphics (OpenGL, Vulkan, Metal, etc.) commands with scene graph rendering, it is necessary to call this function after recording commands to the command buffer used by the scene graph to render its main render pass. This is to avoid clobbering state.

In practice this function is often called from a slot connected to the beforeRenderPassRecording() or afterRenderPassRecording() signals.

The function does not need to be called when recording commands to the application’s own command buffer (such as, a VkCommandBuffer or MTLCommandBuffer + MTLRenderCommandEncoder created and managed by the application, not retrieved from the scene graph). With graphics APIs where no native command buffer concept is exposed (OpenGL, Direct 3D 11), beginExternalCommands() and together provide a replacement for resetOpenGLState() .

Calling this function and beginExternalCommands() is not necessary within the render() implementation of a QSGRenderNode because the scene graph performs the necessary steps implicitly for render nodes.

注意

This function has no effect when the scene graph is using OpenGL directly and the RHI graphics abstraction layer is not in use. Refer to resetOpenGLState() in that case.

另请参阅

beginExternalCommands()

PySide2.QtQuick.QQuickWindow. frameSwapped ( ) ¶

PySide2.QtQuick.QQuickWindow. grabWindow ( ) ¶

返回类型

QImage

Grabs the contents of the window and returns it as an image.

It is possible to call the function when the window is not visible. This requires that the window is created and has a valid size and that no other QQuickWindow instances are rendering in the same process.

警告

Calling this function will cause performance problems.

警告

This function can only be called from the GUI thread.

static PySide2.QtQuick.QQuickWindow. hasDefaultAlphaBuffer ( ) ¶

返回类型

bool

Returns whether to use alpha transparency on newly created windows.

另请参阅

setDefaultAlphaBuffer()

PySide2.QtQuick.QQuickWindow. incubationController ( ) ¶

返回类型

QQmlIncubationController

Returns an incubation controller that splices incubation between frames for this window. QQuickView automatically installs this controller for you, otherwise you will need to install it yourself using setIncubationController() .

The controller is owned by the window and will be destroyed when the window is deleted.

PySide2.QtQuick.QQuickWindow. isPersistentOpenGLContext ( ) ¶

返回类型

bool

Returns whether the OpenGL context can be released during the lifetime of the QQuickWindow .

注意

This is a hint. When and how this happens is implementation specific. It also only has an effect when using the default OpenGL scene graph adaptation

PySide2.QtQuick.QQuickWindow. isPersistentSceneGraph ( ) ¶

返回类型

bool

Returns whether the scene graph nodes and resources can be released during the lifetime of this QQuickWindow .

注意

This is a hint. When and how this happens is implementation specific.

PySide2.QtQuick.QQuickWindow. isSceneGraphInitialized ( ) ¶

返回类型

bool

Returns true if the scene graph has been initialized; otherwise returns false.

PySide2.QtQuick.QQuickWindow. mouseGrabberItem ( ) ¶

返回类型

QQuickItem

Returns the item which currently has the mouse grab.

PySide2.QtQuick.QQuickWindow. openglContext ( ) ¶

返回类型

QOpenGLContext

Returns the OpenGL context used for rendering.

注意

If the scene graph is not ready, or the scene graph is not using OpenGL (or RHI over OpenGL), this function will return null.

另请参阅

sceneGraphInitialized() sceneGraphInvalidated()

PySide2.QtQuick.QQuickWindow. openglContextCreated ( context ) ¶

参数

context – QOpenGLContext

PySide2.QtQuick.QQuickWindow. releaseResources ( ) ¶

This function tries to release redundant resources currently held by the QML scene.

Calling this function might result in the scene graph and the OpenGL context used for rendering being released to release graphics memory. If this happens, the sceneGraphInvalidated() signal will be called, allowing users to clean up their own graphics resources. The setPersistentOpenGLContext() and setPersistentSceneGraph() functions can be used to prevent this from happening, if handling the cleanup is not feasible in the application, at the cost of higher memory usage.

另请参阅

sceneGraphInvalidated() setPersistentOpenGLContext() setPersistentSceneGraph()

PySide2.QtQuick.QQuickWindow. renderTarget ( ) ¶

返回类型

QOpenGLFramebufferObject

Returns the render target for this window.

The default is to render to the surface of the window, in which case the render target is 0.

注意

This function will return nullptr when not using the OpenGL scene graph adaptation.

注意

This function has no effect and returns nullptr when running on the RHI graphics abstraction.

另请参阅

setRenderTarget()

PySide2.QtQuick.QQuickWindow. renderTargetId ( ) ¶

返回类型

uint

Returns the FBO id of the render target when set; otherwise returns 0.

PySide2.QtQuick.QQuickWindow. renderTargetSize ( ) ¶

返回类型

QSize

Returns the size of the currently set render target; otherwise returns an empty size.

PySide2.QtQuick.QQuickWindow. resetOpenGLState ( ) ¶

Call this function to reset the OpenGL context its default state.

The scene graph uses the OpenGL context and will both rely on and clobber its state. When mixing raw OpenGL commands with scene graph rendering, this function provides a convenient way of resetting the OpenGL context state back to its default values.

This function does not touch state in the fixed-function pipeline.

This function does not clear the color, depth and stencil buffers. Use setClearBeforeRendering to control clearing of the color buffer. The depth and stencil buffer might be clobbered by the scene graph renderer. Clear these manually on demand.

注意

This function only has an effect when using the default OpenGL scene graph adaptation.

注意

This function will only reset the OpenGL context in relation to what has been changed internally as part of the OpenGL scene graph. It does not reset anything that has been changed externally such as direct OpenGL calls done inside the application code if those same calls are not used internally.

注意

This function has no effect when running on the RHI graphics abstraction and the underlying RHI backend is not OpenGL.

另请参阅

beforeRendering() beginExternalCommands() endExternalCommands()

PySide2.QtQuick.QQuickWindow. sceneGraphAboutToStop ( ) ¶

static PySide2.QtQuick.QQuickWindow. sceneGraphBackend ( ) ¶

返回类型

unicode

Returns the requested Qt Quick scenegraph backend.

注意

The return value of this function may still be outdated by subsequent calls to setSceneGraphBackend() until the first QQuickWindow in the application has been constructed.

另请参阅

setSceneGraphBackend()

PySide2.QtQuick.QQuickWindow. sceneGraphError ( error , message ) ¶

参数

• error – SceneGraphError

• message – unicode

PySide2.QtQuick.QQuickWindow. sceneGraphInitialized ( ) ¶

PySide2.QtQuick.QQuickWindow. sceneGraphInvalidated ( ) ¶

PySide2.QtQuick.QQuickWindow. scheduleRenderJob ( job , schedule ) ¶

参数

• job – QRunnable

• schedule – RenderStage

Schedules job to run when the rendering of this window reaches the given stage .

This is a convenience to the equivalent signals in QQuickWindow for “one shot” tasks.

The window takes ownership over job and will delete it when the job is completed.

If rendering is shut down before job has a chance to run, the job will be run and then deleted as part of the scene graph cleanup. If the window is never shown and no rendering happens before the QQuickWindow is destroyed, all pending jobs will be destroyed without their run() method being called.

If the rendering is happening on a different thread, then the job will happen on the rendering thread.

若 stage is NoStage , job will be run at the earliest opportunity whenever the render thread is not busy rendering a frame. If there is no OpenGL context available or the window is not exposed at the time the job is either posted or handled, it is deleted without executing the run() method. If a non-threaded renderer is in use, the run() method of the job is executed synchronously. The OpenGL context is changed to the renderer context before executing a NoStage job.

注意

This function does not trigger rendering; the jobs targeting any other stage than NoStage will be stored run until rendering is triggered elsewhere. To force the job to run earlier, call update() ;

另请参阅

beforeRendering() afterRendering() beforeSynchronizing() afterSynchronizing() frameSwapped() sceneGraphInvalidated()

PySide2.QtQuick.QQuickWindow. sendEvent ( arg__1 , arg__2 ) ¶

参数

• arg__1 – QQuickItem

• arg__2 – QEvent

返回类型

bool

注意

此函数被弃用。

Propagates an event e 到 QQuickItem item on the window.

使用 sendEvent() directly instead.

The return value is currently not used.

PySide2.QtQuick.QQuickWindow. setClearBeforeRendering ( enabled ) ¶

参数

enabled – bool

Sets whether the scene graph rendering of QML should clear the color buffer before it starts rendering to enabled .

By disabling clearing of the color buffer, it is possible to render OpengGL content under the scene graph.

The color buffer is cleared by default.

警告

This flag is ignored completely when running with the RHI graphics abstraction instead of using OpenGL directly. As explicit clear commands simply do not exist in some modern APIs, the scene graph cannot offer this flexibility anymore. The images associated with a render target will always get cleared when a render pass starts. As a solution, an alternative to disabling scene graph issued clears is provided in form of the beforeRenderPassRecording() 信号。

另请参阅

clearBeforeRendering() beforeRendering() beforeRenderPassRecording()

PySide2.QtQuick.QQuickWindow. setColor ( color ) ¶

参数

color – QColor

另请参阅

color()

static PySide2.QtQuick.QQuickWindow. setDefaultAlphaBuffer ( useAlpha ) ¶

参数

useAlpha – bool

useAlpha specifies whether to use alpha transparency on newly created windows.

In any application which expects to create translucent windows, it’s necessary to set this to true before creating the first QQuickWindow . The default value is false.

另请参阅

hasDefaultAlphaBuffer()

PySide2.QtQuick.QQuickWindow. setPersistentOpenGLContext ( persistent ) ¶

参数

persistent – bool

Sets whether the OpenGL context should be preserved, and cannot be released until the last window is deleted, to persistent . The default value is true.

The OpenGL context can be released to free up graphics resources when the window is obscured, hidden or not rendering. When this happens is implementation specific.

aboutToBeDestroyed() signal is emitted from the openglContext() when the OpenGL context is about to be released. The sceneGraphInitialized() signal is emitted when a new OpenGL context is created for this window. Make a DirectConnection to these signals to be notified.

The OpenGL context is still released when the last QQuickWindow 被删除。

注意

This only has an effect when using the default OpenGL scene graph adaptation.

另请参阅

isPersistentOpenGLContext() setPersistentSceneGraph() aboutToBeDestroyed() sceneGraphInitialized()

PySide2.QtQuick.QQuickWindow. setPersistentSceneGraph ( persistent ) ¶

参数

persistent – bool

Sets whether the scene graph nodes and resources can be released to persistent . The default value is true.

The scene graph nodes and resources can be released to free up graphics resources when the window is obscured, hidden or not rendering. When this happens is implementation specific.

sceneGraphInvalidated() signal is emitted when cleanup occurs. The sceneGraphInitialized() signal is emitted when a new scene graph is recreated for this window. Make a DirectConnection to these signals to be notified.

The scene graph nodes and resources are still released when the last QQuickWindow 被删除。

另请参阅

isPersistentSceneGraph() setPersistentOpenGLContext() sceneGraphInvalidated() sceneGraphInitialized()

PySide2.QtQuick.QQuickWindow. setRenderTarget ( fbo ) ¶

参数

fbo – QOpenGLFramebufferObject

Sets the render target for this window to be fbo .

The specified fbo must be created in the context of the window or one that shares with it.

注意

This function only has an effect when using the default OpenGL scene graph adaptation.

注意

This function has no effect when running on the RHI graphics abstraction.

警告

This function can only be called from the thread doing the rendering.

另请参阅

renderTarget()

PySide2.QtQuick.QQuickWindow. setRenderTarget ( fboId , size ) ¶

参数

• fboId – uint

• size – QSize

这是重载函数。

Sets the render target for this window to be an FBO with fboId and size .

The specified FBO must be created in the context of the window or one that shares with it.

注意

fboId can also be set to 0. In this case rendering will target the default framebuffer of whichever surface is current when the scenegraph renders. size must still be valid, specifying the dimensions of the surface.

注意

This function only has an effect when using the default OpenGL scene graph adaptation.

警告

This function can only be called from the thread doing the rendering.

static PySide2.QtQuick.QQuickWindow. setSceneGraphBackend ( backend ) ¶

参数

backend – unicode

static PySide2.QtQuick.QQuickWindow. setTextRenderType ( renderType ) ¶

参数

renderType – TextRenderType

Sets the default render type of text-like elements in Qt Quick to renderType .

注意

setting the render type will only affect elements created afterwards; the render type of existing elements will not be modified.

另请参阅

textRenderType()

static PySide2.QtQuick.QQuickWindow. textRenderType ( ) ¶

返回类型

TextRenderType

Returns the render type of text-like elements in Qt Quick. The default is QtTextRendering .

另请参阅

setTextRenderType()

PySide2.QtQuick.QQuickWindow. update ( ) ¶

Schedules the window to render another frame.

Calling differs from update() in that it always triggers a repaint, regardless of changes in the underlying scene graph or not.