Qt-context menu checkable property - qt

Question

I have a context menu option in my UI. where it has white and black theme.
void MainWindow::ShowContextMenu(const QPoint& pos)
{
QPoint globalPos = this->mapToGlobal(pos);
white=new QAction("White", this);
black=new QAction("Black", this);
QMenu myMenu;
theme=myMenu.addMenu(tr("&Theme"));
theme->addAction(white);
theme->addAction(black);
white->setCheckable(true);
black->setCheckable(true);
QActionGroup *grp= new QActionGroup(this);
grp->addAction(white);
grp->addAction(black);
black->setChecked(true);
grp->setExclusive(true);
QAction* selectedItem = myMenu.exec(globalPos);
}
I tried to add group action. Which has default exclusion effect. when i select white the black check should go. and viceversa.
But in my code black menu from the list is always checked. and on selecting white, white menu is not getting checked and black check has check mark.
some one provide me a solution for this.
I want the check mark should be changed and toggled.

Answer 1

In your ShowContextMenu slot you always create a new menu object and check its 'black' option. You should declare a menu object as a MainWindow member and init it once only:
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
myMenu(0), white(0), black(0)
{
...
}
void Widget::initMenu()
{
white=new QAction("White", this);
black=new QAction("Black", this);
myMenu = new QMenu(this);
QMenu *theme= myMenu->addMenu(tr("&Theme"));
theme->addAction(white);
theme->addAction(black);
white->setCheckable(true);
black->setCheckable(true);
QActionGroup *grp= new QActionGroup(this);
grp->addAction(white);
grp->addAction(black);
black->setChecked(true);
grp->setExclusive(true);
}
void Widget::ShowContextMenu(const QPoint& pos)
{
if (!myMenu)
{
initMenu();
}
QPoint globalPos = this->mapToGlobal(pos);
QAction* selectedItem = myMenu->exec(globalPos);
}