編輯:我提供了一個答案,但我很樂意接受另一個提供解釋。Qt信號的繼承?
我爲QPushButton
添加了一些功能,但在將clicked
信號連接到一個插槽後,它不會被調用。如果我使用香草QPushButton,並且不改變其他任何東西,它就會起作用。下面的代碼:
/// --- imagebutton.h
#ifndef IMAGEBUTTON_H
#define IMAGEBUTTON_H
#include <QPushButton>
#include <QImage>
enum ButtonState
{
Normal,
MouseOver,
Pushed
};
class ImageButton : public QPushButton
{
Q_OBJECT
private:
ButtonState state;
public:
QImage *NormalImage;
QImage *MouseOverImage;
QImage *PushedImage;
public:
explicit ImageButton(QWidget *parent = 0);
virtual ~ImageButton();
void enterEvent(QEvent *e);
void leaveEvent(QEvent *e);
void mousePressEvent(QMouseEvent *e);
void mouseReleaseEvent(QMouseEvent *e);
void paintEvent(QPaintEvent *e);
signals:
public slots:
};
#endif // IMAGEBUTTON_H
/// --- imagebutton.cpp
#include <QPainter>
#include "imagebutton.h"
ImageButton::ImageButton(QWidget *parent) :
QPushButton(parent)
{
state = Normal;
}
void ImageButton::enterEvent(QEvent *e)
{
QPushButton::enterEvent(e);
state = MouseOver;
this->repaint();
}
void ImageButton::leaveEvent(QEvent *e)
{
QPushButton::leaveEvent(e);
state = Normal;
this->repaint();
}
void ImageButton::mousePressEvent(QMouseEvent *e)
{
QPushButton::mousePressEvent(e);
state = Pushed;
this->repaint();
}
void ImageButton::mouseReleaseEvent(QMouseEvent *e)
{
QPushButton::mousePressEvent(e);
state = MouseOver;
this->repaint();
}
void ImageButton::paintEvent(QPaintEvent *e)
{
QPainter painter(this);
QImage *pic = NULL;
switch (state)
{
case Normal:
pic = NormalImage;
break;
case MouseOver:
pic = MouseOverImage;
break;
case Pushed:
pic = PushedImage;
break;
default:
pic = NormalImage;
break;
}
painter.drawImage(0, 0, *pic);
}
ImageButton::~ImageButton()
{
delete NormalImage;
delete MouseOverImage;
delete PushedImage;
}
這就是我如何連接信號:
void MainWindow::initInterface()
{
ImageButton *btn_start = new ImageButton(ui->page);
btn_start->setText("start");
connect(btn_start, SIGNAL(clicked()), this, SLOT(btn_clicked()));
// more buttons connected to the same slot
}
什麼可能是這裏的問題?
連接是否返回true或false?如果它是錯誤的控制檯輸出是什麼?它應該打印一些調試信息,如果它是一個調試版本。 – 2010-07-31 14:52:20
它返回true,並且沒有輸出(儘管它是一個調試版本)。 – 2010-07-31 14:58:19