after fighting one hour with QAction in Qt 4.7.0, I found this problem:

I had a function like this:

void Visualizer::AddPlugin(QString plugin_name, PluginInterface* plugin)
{
QAction* plugin_action=new QAction( plugin_name,this);
this->pluginmenu_->addAction(plugin_action);
}

It did not work for me!!! the action name should be hard-coded first. no idea why!? QAction accepts QString &text as first argument. It should be some problem in QString class. It did not work even with plugin_action.setText(plugin_name);

I have changed the class into this:

void Visualizer::AddPlugin(QString plugin_name, PluginInterface* plugin)
{
QAction* plugin_action=new QAction( “”,this);
this->pluginmenu_->addAction(plugin_action);
plugin_action->setText(plugin_name);
}

I don’t find these issues really funny

I really liked this feature in Qt. today I found a really easy method to print a QWidget. nice thing is, if you want to hide some particulare objects in your QWidget before printing you don’t need to delete them, but only set their visibility to false and after the user close the print dialog, set it to true again.

QPrinter *printer = new QPrinter;

QPrintDialog *printDialog = new QPrintDialog(printer,      this);

if (printDialog->exec() == QDialog::Accepted)

{

QPainter p(printer);

QPixmap pixmap(this->size());

this->render(&pixmap);

p.scale(0.60,0.60); // if your widget is bigger than your default paper size

p.drawPixmap(0, 0, pixmap);

}