调用未连接的Qt插槽.调用未连接的

插槽我有一个名为btnStart的QPushButton在mi ClassA.ui 上

并且在头文件ClassA.h:中

private slots:
    void on_btnQuit_clicked();

当我点击按钮btnStart进入插槽on_btnQuit_clickd（）时，但我没有连接任何东西。

classA.h
class classA : public QDialog
{
    Q_OBJECT
public:
    classA( QWidget *parent = 0 );
    ~classA();
private:
    Ui::classA* m_ui;
private slots:
    void on_btnStart_clicked();
};

classA.cpp

#include "ClassA.h"
#include "ui_ClassA.h"
ClassA::ClassA( QWidget *parent ):
    QDialog( parent ),
    m_ui( new Ui::classA )
{
    m_ui->setupUi( this );
}
ClassA::~ClassA()
{
   SWT_DENULL( m_ui );
}
void ClassA::on_btnStart_clicked()
{
    //here
}

classA.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>classA</class>
 <widget class="QDialog" name="classA">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>667</width>
    <height>433</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>title</string>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout">
   <item>
    <layout class="QHBoxLayout" name="horizontalLayout_2">
     <item>
      <widget class="QPushButton" name="btnStart">
       <property name="text">
        <string>Start title</string>
       </property>
      </widget>
     </item>
    </layout>
   </item>
  </layout>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>