How to capture the current screen image using Qt? - qt

Question

I have a button in my Custom QDialog, I am emitting a signal when pushbutton 1 is clicked
void MyCustomDialog::on_pushButton_1()
{
this->hide(); //i need to hide this window before 'OnButton_1_Clicked' stuffs starts
emit button_1_clicked();
}
In my main window I have connected the slot and created the instance as shown below
void MainWindow::MainWindow()
{
MyCustomDialog *dlg = MyCustomDialog::getInstance(this); //only single instance created
connect(dlg, &MyCustomDialog::button_1_clicked, this, &MainWindow::OnButton_1_Clicked);
}
I am displaying my custom dialog from a function in mainwindow as below
void MainWindow::dispayCustomDialog()
{
MyCustomDialog *dlg = MyCustomDialog::getInstance();
dlg->show();
}
Below shows how my 'OnButton_1_Clicked' slot. In which I am capturing the screenshot using below line
void MainWindow::OnButton_1_Clicked()
{
//capture the screen shot
QScreen *screen = QGuiApplication::primaryScreen();
QPixmap *map = new QPixmap(screen->grabWindow(0));
bool result = map->save("D:/test.jpg", "JPG");
}
Once I captured screen using above function, I can still see my 'MyCustomDialog' in test.jpg file. Qt doc says QGuiApplication::primaryScreen captures the initial state of application. So i think, this is expected in my case. Do we have any other solution to grab screen with current state ?
What I am trying to achieve is grab the screen in OnButton_1_Clicked() function after hiding my 'MyCustomDialog'.

Answer 1

I found a solution. Used a singleslot timer with delay of 500 msec before capturing the screen as below. This wait for my custom dialog to hide properly.
void MainWindow::OnButton_1_Clicked()
{
QTimer::singleShot(500, this, &MainWindow::shootscreen);
}
void MainWindow::shootscreen()
{
//capture the screen shot
QScreen *screen = QGuiApplication::primaryScreen();
QPixmap map = screen->grabWindow(0);
bool result = map.save("D:/test.jpg", "JPG");
}