Qt学习1

Action 的用法

首先在头文件的 private 中加：

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QMenu *fileMenu; QMenu *editMenu; QMenu *helpMenu;

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void MainWindow::createActions() //! [17] //! [18] {     newAct = new QAction(QIcon(":/images/new.png"), tr("&New"), this);     newAct->setShortcuts(QKeySequence::New);     newAct->setStatusTip(tr("Create a new file"));     connect(newAct, SIGNAL(triggered()), this, SLOT(newFile()));   //! [19]     openAct = new QAction(QIcon(":/images/open.png"), tr("&Open..."), this);     openAct->setShortcuts(QKeySequence::Open);     openAct->setStatusTip(tr("Open an existing file"));     connect(openAct, SIGNAL(triggered()), this, SLOT(open())); }

menubar

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fileMenu = menuBar()->addMenu(tr("&File"));     fileMenu->addAction(newAct); //! [28]     fileMenu->addAction(openAct); //! [28]     fileMenu->addAction(saveAct); //! [26]     fileMenu->addAction(saveAsAct);     fileMenu->addSeparator();     fileMenu->addAction(exitAct);       editMenu = menuBar()->addMenu(tr("&Edit"));     editMenu->addAction(cutAct);     editMenu->addAction(copyAct);     editMenu->addAction(pasteAct);

toolbar

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fileToolBar = addToolBar(tr("File"));     fileToolBar->addAction(newAct); //! [29] //! [31]     fileToolBar->addAction(openAct); //! [31]     fileToolBar->addAction(saveAct);       editToolBar = addToolBar(tr("Edit"));     editToolBar->addAction(cutAct);     editToolBar->addAction(copyAct);     editToolBar->addAction(pasteAct);

Qsetting

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QSettings settings("QtProject", "Application Example"); settings.setValue("pos", pos()); settings.setValue("size", size());

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QSettings settings("QtProject", "Application Example"); QPoint pos = settings.value("pos", QPoint(200, 200)).toPoint(); QSize size = settings.value("size", QSize(400, 400)).toSize();

打开文本文件

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void MainWindow::open() //! [7] //! [8] {     if (maybeSave()) {         QString fileName = QFileDialog::getOpenFileName(this);         if (!fileName.isEmpty())             loadFile(fileName);     } }

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void MainWindow::loadFile(const QString &fileName) //! [42] //! [43] {     QFile file(fileName);     if (!file.open(QFile::ReadOnly | QFile::Text)) {         QMessageBox::warning(this, tr("Application"),                              tr("Cannot read file %1:\n%2.")                              .arg(fileName)                              .arg(file.errorString()));         return;     }       QTextStream in(&file); #ifndef QT_NO_CURSOR     QApplication::setOverrideCursor(Qt::WaitCursor); #endif     textEdit->setPlainText(in.readAll()); #ifndef QT_NO_CURSOR     QApplication::restoreOverrideCursor(); #endif       setCurrentFile(fileName);     statusBar()->showMessage(tr("File loaded"), 2000); }

文本文件保存

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bool MainWindow::saveAs() //! [11] //! [12] {     QString fileName = QFileDialog::getSaveFileName(this);     if (fileName.isEmpty())         return false;       return saveFile(fileName); }

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bool MainWindow::saveFile(const QString &fileName) //! [44] //! [45] {     QFile file(fileName);     if (!file.open(QFile::WriteOnly | QFile::Text)) {         QMessageBox::warning(this, tr("Application"),                              tr("Cannot write file %1:\n%2.")                              .arg(fileName)                              .arg(file.errorString()));         return false;     }       QTextStream out(&file); #ifndef QT_NO_CURSOR     QApplication::setOverrideCursor(Qt::WaitCursor); #endif     out << textEdit->toPlainText(); #ifndef QT_NO_CURSOR     QApplication::restoreOverrideCursor(); #endif       setCurrentFile(fileName);     statusBar()->showMessage(tr("File saved"), 2000);     return true; }

来自为知笔记(Wiz)