一、主窗口的概念
1、应用程序中的主窗口
(1)、主窗口是与用户进行长时间交互的顶级窗口
(2)、程序的绝大多数功能直接由主窗口提供
(3)、主窗口通常是应用程序启动后显示的第一个窗口
(4)、整个程序由一个主窗口和多个对话框组成
2、Qt中的主窗口
(1)、Qt开发平台中直接支持主窗口的概念
(2)、QMainWindow是Qt中主窗口的基类
(3)、QMainWindow是继承于QWidget的一种容器类组件
3、QMainWindow中封装的秘密
4、QMainWindow中组件布局
二、主窗口中的菜单
1、在Qt中提供与菜单相关的类组件
2、在主窗口中创建菜单
3、快捷键的设置
思路:三板斧
(1)、菜单栏函数里创建菜单栏对象,并且调用菜单函数(参数为菜单栏对象)
(2)、菜单函数里创建菜单,并且调用菜单项函数(参数为返回菜单项的引用、菜单项的名字、快捷键),添加菜单项到菜单,添加菜单到菜单栏
(3)、菜单项函数里创建菜单项,设置菜单项名字和快捷键(父组件先不用设置)
MainWindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMenuBar>
#include <QMenu>
#include <QAction>
#include <QString>
#include <QtGui/QMainWindow>
class MainWindow : public QMainWindow
{
Q_OBJECT
private:
MainWindow(QWidget *parent = 0);
MainWindow(const MainWindow& obj);
MainWindow* operator = (const MainWindow& obj);
bool construct();
bool initMenuBar();//菜单栏
bool initFileMenu(QMenuBar* mb);//文件菜单
bool initEditMenu(QMenuBar* mb);//编辑菜单
bool initFormatMenu(QMenuBar* mb);//格式菜单
bool initViewMenu(QMenuBar* mb);//视图菜单
bool initHelpMenu(QMenuBar* mb);//帮助菜单
bool makeAction(QAction*& action, QString text, int ket);//菜单项
public:
static MainWindow* NewInstance();
~MainWindow();
};
#endif // MAINWINDOW_H
MainWindow.h
MainWindow.cpp
#include "MainWindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
}
bool MainWindow::construct()
{
bool ret = true;
ret = ret && initMenuBar();
return ret;
}
MainWindow* MainWindow::NewInstance()
{
MainWindow* ret = new MainWindow();
if((ret==NULL) || (!ret->construct()))
{
delete ret;
ret = NULL;
}
return ret;
}
bool MainWindow::initMenuBar()//菜单栏
{
bool ret = true;
QMenuBar* mb = menuBar();//一定要注意是menuBar(),这是普通成员函数,不是构造函数
ret = ret && initFileMenu(mb);//传一个参数是为了在initFileMenu()函数将menu加入菜单栏
ret = ret && initEditMenu(mb);
ret = ret && initFormatMenu(mb);
ret = ret && initViewMenu(mb);
ret = ret && initHelpMenu(mb);
return ret;
}
/************************************************文件菜单********************************************************/
bool MainWindow::initFileMenu(QMenuBar* mb)
{
bool ret = true;
QMenu* menu = new QMenu("File(&F)");//创建文件菜单,(&F)是为了可以Alt+F打开
ret = (menu != NULL);
if(ret)
{
QAction* action = NULL;
//New
ret = ret && makeAction(action, "New(&N)",Qt::CTRL + Qt::Key_N);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Open
ret = ret && makeAction(action, "Open(&O)...",Qt::CTRL + Qt::Key_O);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Save
ret = ret && makeAction(action, "Save(&S)",Qt::CTRL + Qt::Key_S);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Save As
ret = ret && makeAction(action, "Save As(&A)...",0);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//print
ret = ret && makeAction(action, "Print(&P)...",Qt::CTRL + Qt::Key_P);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Exit
ret = ret && makeAction(action, "Exit(&X)",0);
if(ret)
{
menu->addAction(action);//将菜单项加入到菜单
}
}
if(ret)
{
mb->addMenu(menu);//将菜单加入到菜单栏
}
else
{
delete mb;
}
return ret;
}
/************************************************编辑菜单********************************************************/
bool MainWindow::initEditMenu(QMenuBar* mb)
{
bool ret = true;
QMenu* menu = new QMenu("Edit(&E)");
ret = (menu != NULL);
if(ret)
{
QAction* action = NULL;
//Undo
ret = ret && makeAction(action, "Undo(&U)",Qt::CTRL + Qt::Key_Z);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Redo
ret = ret && makeAction(action, "Redo(&R)...",Qt::CTRL + Qt::Key_Y);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Cut
ret = ret && makeAction(action, "Cut(&T)",Qt::CTRL + Qt::Key_X);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Copy
ret = ret && makeAction(action, "Copy(&C)...",Qt::CTRL + Qt::Key_C);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Pase
ret = ret && makeAction(action, "Pase(&P)...",Qt::CTRL + Qt::Key_V);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Delete
ret = ret && makeAction(action, "Delete(&L)",Qt::Key_Delete);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Find
ret = ret && makeAction(action, "Find(&F)...",Qt::CTRL + Qt::Key_F);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Replace
ret = ret && makeAction(action, "Replace(&R)...",Qt::CTRL + Qt::Key_H);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Goto
ret = ret && makeAction(action, "Goto(&G)",Qt::CTRL + Qt::Key_G);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Select All
ret = ret && makeAction(action, "Select All(&A)",Qt::CTRL + Qt::Key_A);
if(ret)
{
menu->addAction(action);
}
}
if(ret)
{
mb->addMenu(menu);
}
else
{
delete mb;
}
return ret;
}
/************************************************格式菜单********************************************************/
bool MainWindow::initFormatMenu(QMenuBar* mb)
{
bool ret = true;
QMenu* menu = new QMenu("Format(&O)");
ret = (menu != NULL);
if(ret)
{
QAction* action = NULL;
//Auto Wrap
ret = ret && makeAction(action, "Auto Wrap(&W)",0);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Font
ret = ret && makeAction(action, "Font(&F)...",0);
if(ret)
{
menu->addAction(action);
}
}
if(ret)
{
mb->addMenu(menu);
}
else
{
delete mb;
}
return ret;
}
/************************************************视图菜单********************************************************/
bool MainWindow::initViewMenu(QMenuBar* mb)
{
bool ret = true;
QMenu* menu = new QMenu("View(&V)");
ret = (menu != NULL);
if(ret)
{
QAction* action = NULL;
//Tool Bar
ret = ret && makeAction(action, "Tool Bar(&T)",0);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//Status Bar
ret = ret && makeAction(action, "Status Bar(&S)",0);
if(ret)
{
menu->addAction(action);
}
}
if(ret)
{
mb->addMenu(menu);
}
else
{
delete mb;
}
return ret;
}
/************************************************帮助菜单********************************************************/
bool MainWindow::initHelpMenu(QMenuBar* mb)
{
bool ret = true;
QMenu* menu = new QMenu("Help(&H)");
ret = (menu != NULL);
if(ret)
{
QAction* action = NULL;
//User Manual
ret = ret && makeAction(action, "User Manual",0);
if(ret)
{
menu->addAction(action);
}
menu->addSeparator();
//About NotePad
ret = ret && makeAction(action, "About NotePad...",0);
if(ret)
{
menu->addAction(action);
}
}
if(ret)
{
mb->addMenu(menu);
}
else
{
delete mb;
}
return ret;
}
bool MainWindow::makeAction(QAction*& action, QString text, int key)//菜单项
{
bool ret = true;
action = new QAction(text, NULL);
if(action != NULL)
{
action->setShortcut(QKeySequence(key));//创建快捷键
}
else
{
ret = false;
}
return ret;
}
MainWindow::~MainWindow()
{
}
MainWindow.cpp
main.cpp
#include <QtGui/QApplication>
#include "MainWindow.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow* w = MainWindow::NewInstance();
w->show();
return a.exec();
}
main.cpp
三、小结
(1)、主窗口是与用户进行长时间交互的顶级窗口
(2)、主窗口通常是应用程序启动后显示的第一个窗口
(3)、QMainWindow是Qt中主窗口的基类
(4)、QMainWindow是继承于QWidget的一种容器类组件
(5)、QMainWindow封装了菜单栏、工具栏、状态栏等组件