3.关于QT中的MainWindow窗口，MenuBar,ToolBar,QuickTip等方面的知识点

编写12MainWindow.pro

HEADERS += \

    MyMainWindow.h \

    MyView.h

SOURCES += \

    MyMainWindow.cpp \

    MyView.cpp

QT += gui widgets

MyView.h

#ifndef MYVIEW_H

#define MYVIEW_H

#include <QWidget>

class MyView:public QWidget{

    Q_OBJECT

public:

    explicit MyView(QWidget *parent = 0);

    void paintEvent(QPaintEvent *);

signals:

public slots:

};

#endif // MYVIEW_H

MyView.cpp

#include "MyView.h"

#include <QPainter>

MyView::MyView(QWidget *parent):

    QWidget(parent)

{

}

void MyView::paintEvent(QPaintEvent *)

{

    QPainter p(this);

    p.fillRect(rect(),Qt::red);

}

MyMainWindow.h

#ifndef MYMAINWINDOW_H

#define MYMAINWINDOW_H

#include <QMainWindow>

#include <QLabel>

#include "MyView.h"

#include <QSystemTrayIcon>  //通过这个头文件可以让程序在状态栏显示icon

class MyMainWindow:public QMainWindow

{

    Q_OBJECT

public:

    explicit MyMainWindow(QWidget *parent = 0);

    QLabel* _label;

    MyView* _view;

    QSystemTrayIcon* _icon;

    void paintEvent(QPaintEvent *);

    void mousePressEvent(QMouseEvent *);

    QMenu* _menu;

    bool event(QEvent *event);

    bool eventFilter(QObject *, QEvent *);

signals:

public slots:

    void slotOpen();

    void slotActivated(QSystemTrayIcon::ActivationReason);

};

#endif // MYMAINWINDOW_H

MyMainWindow.cpp

#include "MyMainWindow.h"

#include <QApplication>

#include <QMenu>

#include <QMenuBar>

#include <QAction>

#include <QDebug>

#include <QFileDialog>

#include <QToolBar>

#include <QStatusBar>

#include <QLabel>

#include <QPixmap>

#include <QPainter>

#include <QMouseEvent>

#include <QCursor>

#include <QIcon>

MyMainWindow::MyMainWindow(QWidget *parent):

    QMainWindow(parent)

{

    /*加菜单*/

    QMenuBar* pMenuBar = menuBar();

    QMenu* menu = pMenuBar->addMenu("&File");

    _menu = menu;

    QAction* openAction = menu->addAction("&Open", this, SLOT(slotOpen()), QKeySequence::Open);

    QAction* saveAction = menu->addAction("&Save", this, SLOT(slotOpen()), QKeySequence::Save);

    menu->addSeparator();

    QAction* closeAction = menu->addAction("&Exit", this, SLOT(close()), QKeySequence::Close);

    closeAction->setToolTip("close window");

    /*toolbar 添加工具栏*/

    QToolBar* toolBar = this->addToolBar("MyToolBar");

    toolBar->addAction(openAction);

    toolBar->addAction(saveAction);

    toolBar->addAction(closeAction);

    /* status bar*/

    QStatusBar* pStatusBar = this->statusBar();

    pStatusBar->addWidget(_label = new QLabel("OK"));

    _label->setText("<font color=red>Processing...</font>");

    /* 别的控件占用了之后，剩下的区域都是CentralWidget */

    _view = new MyView;

    this->setCentralWidget(_view);

    //system tray icon

    _icon = new QSystemTrayIcon;

    _icon->setIcon(QIcon("../bing.ico"));

    _icon->setToolTip("This is tray icon test");

    _icon->show();

    _icon->setContextMenu(_menu);

    connect(_icon, SIGNAL(activated(QSystemTrayIcon::ActivationReason)),

                this, SLOT(slotActivated(QSystemTrayIcon::ActivationReason)));

    this->installEventFilter(this);

}

void MyMainWindow::slotActivated(QSystemTrayIcon::ActivationReason reason)

{

    if(reason == QSystemTrayIcon::Trigger)

    {

        if(this->isHidden()) this->show();

        else this->hide();

    }

}

/**

 * @brief MyMainWindow::eventFilter

 * @param o

 * @param e

 * @return 消息过滤器

 */

bool MyMainWindow::eventFilter(QObject *o, QEvent *e)

{

    if(o == (QObject *)this && e->type() == QEvent::Close)

    {

        return true;

    }

    return QMainWindow::eventFilter(o, e);

}

bool MyMainWindow::event(QEvent *ev)

{

    qDebug() << ev;

    if(ev->type() == QEvent::Close)

    {

        return false;

    }

    return QMainWindow::event(ev);

}

void MyMainWindow::mousePressEvent(QMouseEvent *ev)

{

    if(ev->button() == Qt::RightButton)

        _menu->exec(QCursor::pos());

}

void MyMainWindow::paintEvent(QPaintEvent *)

{

    QPainter p(this);

    p.drawPixmap(QPoint(0,0),QPixmap(".../aaa.png"));

}

void MyMainWindow::slotOpen()

{

    QString strFile = QFileDialog::getOpenFileName();

    qDebug() << "Open file is:" << strFile;

}

int main(int argc,char* argv[])

{

    QApplication app(argc,argv);

    MyMainWindow w;

    w.show();

    return app.exec();

}

运行结果：

右键的时候出现菜单