Thanks for the support guys. I tried making a transparent QPixmap image using Qt::transparent fill for the axis and overlaying it onto my other QPixmap, however it didn't work properly. So I ended up just drawing directly onto the image itself. Not the most efficient method but it seems to work...

@rjmoses
Yes it will scale all images to match IconSize.

Hi,
I got the expected output from grab(QRect)
https://stackoverflow.com/questions/16362191/qt-grab-widget-and-save-image

m_graphicsView->grab(rect).save("OUT.jpg");

Thanks all.

@mrjj Thanks for the help

@dheerendra Okay, done, thank you for reminding!

@mdma2
Can you post the full code of this short example, so that it can be tried out immediately using simple copy/paste...

@VRonin Yes, they are, but the pixmap is just grabbed QGraphicsView's content using grab() method.

I found where the problem was!

As Christian Ehrlicher said according to the Documentation QByteArray::fromRawData() only store the pointer to the data. That explain why it doensn't work outside the function since the data goes out of scope. Instead of using this method I used one the constructors that make deep copy of the data. And it just works fine!

QByteArray data (value.dataPointer (), value.dataSize ()); return data;

Thanks all!

Hi,

See my answer one the other thread.

Why create a QList and not do the conversion directly after calling CaptureImage ?

Otherwise, does the library you are using to get the image provide a streaming API ?

Hi,

Can you show how your create the image that you pass to the function ?

Also, can you provide a stack trace of your application crash ?

Yes, a file with size 0 kb is being created

What do you think about this?

int length = this->boundingRect().width(); length = (int)(((double)length * (double)value) / 100.0); QPixmap pix(this->boundingRect().width() - length, this->boundingRect().height()); pix.fill(Qt::transparent); QPainter p; p.begin(&pix); p.fillRect(pix.rect(), QColor(0, 0, 0, 120)); p.end(); gauge->setPixmap(pix); gauge->setPos(pos().x()+length, pos().y());

It works fine and the effect is the same as on example pixtures above.

I have find a way to get a QImage of an QWindow:
Make a standard QWindow with is surface and add the following code:

// set the current context OpenGL // check if an OpenGlContext is created QOpenGLContext context; context.setFormat(format()); if (!context.create()) qFatal("Cannot create the requested OpenGL context!"); context.makeCurrent(this); // init a new framebuffer QOpenGLFramebufferObjectFormat fboFormat; fboFormat.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil); fboFormat.setMipmap(true); fboFormat.setSamples(4); fboFormat.setTextureTarget(GL_TEXTURE_2D); fboFormat.setInternalTextureFormat(GL_RGB); resize(this->width(), this->height()); const QRect drawRect(0, 0, this->width(), this->height()); const QSize drawRectSize = drawRect.size(); _fbo = new QOpenGLFramebufferObject(drawRectSize, fboFormat); _fbo->bind(); ... _fboImage = new QImage(_fbo->toImage(false));

But, this is work only if the window is "visible", when it is set to Hidden the rendering of Qt3D was made (the rendering loop, because the GPU is used and the FPS is divided by 3), but the QOpenGLFramebufferObject was not filled :/

Do you have any idea of how force the filling of the fbo ?

PS: I have found this here : http://stackoverflow.com/questions/17221730/do-offscreen-renderopengl-with-qt5

The QPixmap class has a constructor that takes a QSize parameter and therefore allows you to create a pixmap of a given size. That is what @jsulm is doing in the first line of his last code example. Documentation.

Hi,
QPainter can draw a QImage. So you can for example create a new Widget, subclass for QLabel for example if you want and reimplement paintEvent. Like this you work all the time with your QImage without creating another one.
And better you can only update the region that changed, no need to refresh everything. I did not try it but it should work.
Sincerely

Hi! The way to convert your matrix to a QPixmap is to convert it to QImage first (e.g. using void QImage::setPixel(const QPoint &position, uint index_or_rgb)) and then convert the QImage to a QPixmap (using [static] QPixmap QPixmap::fromImage(const QImage &image, Qt::ImageConversionFlags flags = Qt::AutoColor)).

@kevin32 Great :)

@Rohith : thanks.but your solution does not work for me. I have multi button. I for example want to set image (/pic/1.png) to btn1 and then set another image to another button.
My question How to set image to them in my code behind?