#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); this->setWindowTitle("记事本"); //连接函数，谁发出信息，发出什么信号，谁接收信号，执行什么操作 //自定义三个槽函数，newActionSlot,openActionSlot,saveActionSlot connect(ui->newAction,&QAction::triggered,this,&MainWindow::newActionSlot); connect(ui->openAction,&QAction::triggered,this,&MainWindow::openActionSlot); connect(ui->saveAction,&QAction::triggered,this,&MainWindow::saveActionSlot); } MainWindow::~MainWindow() { delete ui; } void MainWindow::newActionSlot() { //清空内容 ui->textEdit->clear(); this->setWindowTitle("新建文本文档.txt"); } void MainWindow::openActionSlot() { //打开文件资源管理窗口，获取选定的文件的路径 QString filename= QFileDialog::getOpenFileName(this, "打开文件", QCoreApplication::applicationFilePath(), "*.cpp"); if(filename.isEmpty()) { QMessageBox::warning(this,"警告","请打开一个文件！"); } else{ //qDebug() << filename; //通过文件路径，构建文件对象 QFile file(filename); //只读方式打开 file.open(QIODevice::ReadOnly); //读取文件中的所有内容到字节数组中 QByteArray ba = file.readAll(); //关闭文件对象 file.close(); //将读取的数据存储到textEdit中 ui->textEdit->setText(QString(ba)); } } void MainWindow::saveActionSlot() { //弹出文件资源管理器窗口，选择文件夹。 //QCoreApplication::applicationFilePath()表示当前根目录 QString filename=QFileDialog::getSaveFileName(this,"保存文件", QCoreApplication::applicationFilePath()); if(filename.isEmpty()) QMessageBox::warning(this,"警告","请选择一个文件！"); else { QFile file(filename); file.open(QIODevice::WriteOnly); QByteArray ba; ba.append(ui->textEdit->toPlainText().toUtf8()); file.write(ba); file.close(); QMessageBox::about(this,"提示","保存成功"); } } void MainWindow::keyPressEvent(QKeyEvent *k) { //键盘按下事件，一个父类的虚函数，能够检测键盘事件。Ctrl+S调用保存函数 if(k->modifiers()==Qt::ControlModifier&&k->key()==Qt::Key_S) saveActionSlot(); } void MainWindow::mousePressEvent(QMouseEvent *m) { QPoint pt = m->pos(); qDebug()<<pt; if(m->button()==Qt::LeftButton) qDebug()<<"左键被按下"; else if(m->button()==Qt::RightButton) qDebug()<<"右键被按下"; }