I have a QOpenglWidget and a customized QOffscreenSurface,then I set Qt::AA_ShareOpenGLContexts attribute to QCoreApplication,here is my code:

void main(){
    QCoreApplication::setAttribute(Qt::AA_ShareOpenGLContexts);
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
}

mainwindow has a subclass of QOpenglWidget TextureWidget and a subclass of QOffscreenSurface OffscreenRender, I want to share buffer objects and texture objects between these two class.

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    center = new QSplitter();
    center->resize(800,400);

    left = new TextureWidget;
    offscreen = new OffscreenRender(this);

    setCentralWidget(TextureWidget);
}

TextureWidget as below:

class TextureWidget:public QOpenGLWidget,protected QOpenGLFunctions_4_3_Core
{
    Q_OBJECT
public:
    TextureWidget(QWidget* parent = 0);
    ~TextureWidget();    
protected:    
    void initializeGL() override{
        QOpenGLContext *currentContext = context();
        QOpenGLContext *share = currentContext->shareContext();
        initializeOpenGLFunctions();
        glGenVertexArrays(1, &vao);
        glBindVertexArray(vao);
        glGenBuffers(1, &vbo);
        glBindBuffer(GL_ARRAY_BUFFER,vbo);
        ...        
    }
    void paintGL() override{
         ...
    }
    void resizeGL(int width, int height) override{...}
private:
    GLuint vao,vbo;

OffscreenRender code :

class OffscreenRender:public QOffscreenSurface,protected QOpenGLFunctions_4_3_Core
{
    OffscreenRender(QObject *parent = 0){
        setParent(parent);

         QSurfaceFormat  surfaceFormat;
         surfaceFormat.setMajorVersion(4);
         surfaceFormat.setMinorVersion(3);
         surfaceFormat.setProfile(QSurfaceFormat::CoreProfile);

         openGLContext = new QOpenGLContext();
         openGLContext->setFormat(surfaceFormat);
         //set share context with current context explicitly
         QOpenGLContext *share = QOpenGLContext::globalShareContext();
         openGLContext->setShareContext(share);

         if(openGLContext->create()){
             share = openGLContext->shareContext();

             setFormat(surfaceFormat);
             create();
             if(!isValid()) qDebug("Unable to create the Offscreen surface");

             openGLContext->makeCurrent(this);
             glGenVertexArrays(1, &vaoGen);
             glBindVertexArray(vaoGen);
             glGenBuffers(1, &vboGen);
             glBindBuffer(GL_ARRAY_BUFFER,vboGen);
             ...
        }
private:
      GLuint vaoOff,vboOff;
}

I find that share(QOpenGLContext *) in TextureWidget and OffscreenRender are different even after setting Qt::AA_ShareOpenGLContexts attribute,but two vbo are sequential and can be shared.