QT练习 菜单栏，工具栏

原来想做一个简易的文本编辑查看器，最后是个半成品。菜单操作会了////////////////////////////////////#ifndef MAINWINDOW_H#define MAINWINDOW_H#include #include "QMessageBox"#include "QtGui"#include "QFile"#include namespace Ui {class MainWindow;}class MainWindow : public QMainWindow{ Q_OBJECT public: explicit MainWindow(QWidget *parent = 0); ~MainWindow();private slots: void on_action_About_QT_triggered(); void on_action_Exit_triggered(); void on_action_About_triggered(); void on_action_Open_triggered();private: Ui::MainWindow *ui;};#endif // MAINWINDOW_H////////////////////////////////////#include #include "mainwindow.h"int main(int argc, char *argv[]){ QApplication a(argc, argv); QTextCodec::setCodecForCStrings(QTextCodec::codecForName("GB2312")); QTextCodec::setCodecForLocale(QTextCodec::codecForName("GB2312")); QTextCodec::setCodecForTr(QTextCodec::codecForName("GB2312")); MainWindow w; w.show(); return a.exec();}///////////////////////#include "mainwindow.h"#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *