title: Qt: "No such signal" error
body: <p>I have a simple code; here I've two buttons, I press the first one and it shows a MsgBox. Then I press the "Okay", and it <em>should</em> call a connected action written in a second button, but it doesn't. Instead I get an error:</p>
  
  <pre><code>Object::connect: No such signal QMessageBox::buttonClicked(QMessageBox::Ok)
  Object::connect:  (receiver name: 'OpenFile_Bttn')
  </code></pre>
  
  <p>The code:</p>
  
  <pre><code>#include "mainwindow.h"
  #include "ui_mainwindow.h"
  
  MainWindow::MainWindow(QWidget *parent) :
      QMainWindow(parent),
      ui(new Ui::MainWindow)
  {
      ui-&gt;setupUi(this);
  }
  
  MainWindow::~MainWindow()
  {
      delete ui;
  }
  
  void MainWindow::on_OpenFile_Bttn_clicked(){
      QFileDialog::getOpenFileName(this,tr("Open file"), "", tr(""));//Open a dialog "OpenFile"
  }
  
  void MainWindow::on_pushButton_clicked(){
      QMessageBox msgBox;
      msgBox.setText("Push button to choose a file");
      //Connect clicking button in MsgBox to an action in OpenFile_Bttn button
      QWidget::connect(&amp;msgBox,SIGNAL(buttonClicked(QMessageBox::Ok)),
              ui-&gt;OpenFile_Bttn, SLOT(on_OpenFile_Bttn_clicked()));
      msgBox.exec();//Show MsgBox
  }
  </code></pre>
  
  <p>Also I found an interesting thing, that the error message appears when a MsgBox popup, but not when I click the button "Ok" inside the MsgBox.</p>