QActionGroup

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)

    : QMainWindow(parent)

{

    leftAlignAct = new QAction(tr("leftAlignAct"),this);

    leftAlignAct->setCheckable(true);

    rightAlignAct = new QAction(tr("rightAlignAct"),this);

    rightAlignAct->setCheckable(true);

    justifyAct = new QAction(tr("justifyAct"),this);

    justifyAct->setCheckable(true);

    centerAct = new QAction(tr("centerAct"),this);

    centerAct->setCheckable(true);

    leftAlignAct->setChecked(true);

    QToolBar *toolBar = addToolBar(tr("tool"));

    QActionGroup *alignmentGroup = new QActionGroup(toolBar);//或者this？？？？

    alignmentGroup->addAction(leftAlignAct);

    alignmentGroup->addAction(rightAlignAct);

    alignmentGroup->addAction(justifyAct);

    alignmentGroup->addAction(centerAct);  

    toolBar->addAction(leftAlignAct);

    toolBar->addAction(rightAlignAct);

    toolBar->addAction(justifyAct);

    toolBar->addAction(centerAct);

    connect(alignmentGroup,SIGNAL(triggered(QAction*)),this,SLOT(ShowAlignment( QAction *)));

}

void MainWindow::ShowAlignment( QAction *act)

{

    if(act==leftAlignAct)

        QMessageBox::information(NULL, "leftAct","leftAct", QMessageBox::Yes|QMessageBox::No);

    if(act==rightAlignAct)

        QMessageBox::information(NULL, "rightAlignAct","rightAlignAct", QMessageBox::Yes|QMessageBox::No);

    if(act==justifyAct)

        QMessageBox::information(NULL, "justifyAct","justifyAct", QMessageBox::Yes|QMessageBox::No);

    if(act==centerAct)

        QMessageBox::information(NULL, "centerAct","centerAct", QMessageBox::Yes|QMessageBox::No);

}

MainWindow::~MainWindow()

{

}