ljn's 学习笔记
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发表于

learned

  • QFileDialog用于获取需要打开的文件（点击）
  • QFile::open打开文件，readAll()获取QByteArray类型的数据
  • 键与槽函数Qt::ControlModifier,mousePressEvent，QPoint
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if(QKetEvent* k->modifiers()==Qt::ControlModifier && k->key()==Qt::Key_S)
        {
            saveActionSlot();
        }
  • 槽函数的连接（与按键事件）
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connect(ui->newAction,&QAction::triggered,this,&MainWindow::newActionSlot);

code

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#include "mainwindow.h"
#include "./ui_mainwindow.h"
#include <QFileDialog>
#include <QMessageBox>
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    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()
{
    ui->textEdit->clear();
    this->setWindowTitle("新建文本文档.txt");
}

void MainWindow::openActionSlot()
{
    QString fileName = QFileDialog::getOpenFileName(this,"打开",
                                 QCoreApplication::applicationFilePath(),"*.cpp");
    if(fileName.isEmpty())
    {
        QMessageBox::warning(this,"警告","请选择一个文件");
    }
    else
    {
        // qDebug()<<fileName;
        QFile file(fileName);
        file.open(QIODevice::ReadOnly);
        QByteArray ba=file.readAll();
        ui->textEdit->setText(QString(ba));
        file.close();
    }
}

void MainWindow::saveActionSlot()
{
    QString fileName = QFileDialog::getSaveFileName(this,"保存",
                                                    QCoreApplication::applicationFilePath());

    if(fileName.isEmpty())
    {
        QMessageBox::warning(this,"警告","请选择一个文件");
    }
    else
    {
        // qDebug()<<fileName;
        QFile file(fileName);
        file.open(QIODevice::WriteOnly);
        QByteArray ba;
        ba.append(qPrintable(ui->textEdit->toPlainText()));
        file.write(ba);
        file.close();
    }

}

void MainWindow::keyPressEvent(QKeyEvent *k)
{
    if(k->modifiers()==Qt::ControlModifier && k->key()==Qt::Key_S)
    {
        saveActionSlot();
    }
    else if(k->modifiers()==Qt::ControlModifier&&k->key()==Qt::Key_N)
    {
        newActionSlot();
    }
    else if(k->modifiers()==Qt::ControlModifier&&k->key()==Qt::Key_O)
    {
        openActionSlot();
    }
}

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";
    }
}