title: c++ QPushButton signal and slot
body: <p>I have a problem creating a <code>QPushButton</code> and linking its signal to my slots. First, I created a class with the slot:</p>
  <pre><code>class A : public QWidget{
  
    public slots:
      void handleButton();
  
  };
  </code></pre>
  <p>There is my <code>handleButton</code> function in the .cpp</p>
  <pre><code>void A::handleButton(int row, int col){
      m_button-&gt;setText(&quot;Example&quot;);
      // resize button
      m_button-&gt;resize(100,100);
  }
  </code></pre>
  <p>Then I want to connect the button.</p>
  <pre><code>QObject::connect(m_button, SIGNAL(clicked()), qApp, SLOT(handleButton()));
  </code></pre>
  <p>But I got an error when I start the application:</p>
  <pre><code>&quot;No such slot&quot;
  </code></pre>