[英]QEvent Signal and Slot
我创建了一个Qt项目,并添加了一个QPushButton,其样式是使用QEvent和QMouseEvent自定义的。 我在此按钮上添加了一个插槽,但是它不起作用。 这是一个像我的项目:
标头1:
#ifndef MYQPUSHBUTTON_H
#define MYQPUSHBUTTON_H
#include <QPushButton>
#include <QPalette>
class myQPushButton : public QPushButton
{
Q_OBJECT
public:
explicit myQPushButton(QWidget *parent = 0);
~myQPushButton();
void enterEvent(QEvent* );
void leaveEvent(QEvent* );
void mousePressEvent(QMouseEvent * );
void mouseReleaseEvent(QMouseEvent * );
signals:
public slots:
private:
QPalette *palette;
};
#endif // MYQPUSHBUTTON_H
标头2:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "myQPushButton/myqpushbutton.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private:
Ui::MainWindow *ui;
myQPushButton *button;
};
#endif // MAINWINDOW_H
来源1:
#include "myqpushbutton.h"
myQPushButton::myQPushButton(QWidget *parent) :
QPushButton(parent)
{
setFixedSize(200,200);
setIconSize(QSize(200,200));
setIcon(QIcon("D:/clockbox/qt/clockbox/exit_button_wwin_norm.png"));
setFlat(true);
}
myQPushButton::~myQPushButton()
{
}
void myQPushButton::enterEvent(QEvent* )
{
setIcon(QIcon("D:/clockbox/qt/clockbox/exit_button_wwin_enter.png"));
}
void myQPushButton::leaveEvent(QEvent* )
{
setIcon(QIcon("D:/clockbox/qt/clockbox/exit_button_wwin_norm.png"));
}
void myQPushButton::mousePressEvent(QMouseEvent * )
{
setIcon(QIcon("D:/clockbox/qt/clockbox/exit_button_wwin_pressed.png"));
}
void myQPushButton::mouseReleaseEvent(QMouseEvent * )
{
setIcon(QIcon("D:/clockbox/qt/clockbox/exit_button_wwin_enter.png"));
}
来源2:
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
myQPushButton y;
QObject::connect(y, SIGNAL(clicked()), &w, SLOT(close()));
return a.exec();
}
资料来源3:
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
button = new myQPushButton(this);
setCentralWidget(button);
}
MainWindow::~MainWindow()
{
delete ui;
}
我在源2上收到此错误:
错误:没有匹配的函数用于调用'QObject :: connect(myQPushButton&,const char *,MainWindow *,const char *)'QObject :: connect(y,SIGNAL(clicked()),&w,SLOT(close()) ); ^
我希望此按钮成为退出按钮。 有人可以帮助我吗?
为了克服编译错误,您必须更改QObject::connect(y, SIGNAL(clicked()), &w, SLOT(close()));
到QObject::connect(&y, SIGNAL(clicked()), &w, SLOT(close()));
。 QObject :: connect需要发送者的指针。
但这不是这里的问题,您要添加实际上未添加到窗口的按钮的信号(您在main()
创建连接到close
插槽的按钮y
,但稍后在MainWindow
创建一个新的按钮,并将其作为中央窗口小部件添加到MainWindow
中。然后应从main()
删除按钮,并在MainWindow::MainWindow
进行QObject::connect
调用,例如QObject::connect(button, SIGNAL(clicked()), this, SLOT(close()));
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
button = new myQPushButton(this);
QObject::connect(button, SIGNAL(clicked()), this, SLOT(close()));
setCentralWidget(button);
}
MainWindow::~MainWindow()
{
delete ui;
}
主要:
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
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