qt 5.x　初探(1)

May 14, 2017 · 2 min read · qt c++

嘛。。为了系统安全课来学一波qt...

现在算是写出了一个可以打开文件，保存文件的记事本。。。

接下来要搞定的事情是。。。如何写一个自定义的事件。。。比如计算个开方之类的。。。

放一波代码好了。。。

#include <QAction>
#include <QMenuBar>
#include <QMessageBox>
#include <QStatusBar>
#include <QToolBar>
#include <QDebug>
#include <QTextEdit>
#include <QFileDialog>

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{


    openAction = new QAction(QIcon(":/images/file-open"), tr("&Open..."), this);
    openAction->setShortcuts(QKeySequence::Open);
    openAction->setStatusTip(tr("Open an existing file"));

    saveAction = new QAction(QIcon(":/images/file-open"), tr("&Save..."), this);
    saveAction->setShortcuts(QKeySequence::Save);
    saveAction->setStatusTip(tr("Save a new file"));

    QMenu *file = menuBar()->addMenu(tr("&File"));
    file->addAction(openAction);
    file->addAction(saveAction);

    QToolBar *toolBar = addToolBar(tr("&File"));
    toolBar->addAction(openAction);
    toolBar->addAction(saveAction);

    textEdit = new QTextEdit(this);
    setCentralWidget(textEdit);

    connect(openAction, &QAction::triggered, this, &MainWindow::openFile);
    connect(saveAction, &QAction::triggered, this, &MainWindow::saveFile);


}

MainWindow::~MainWindow()
{
}


void MainWindow::openFile()
{
    QString path = QFileDialog::getOpenFileName(this,
                                                tr("Open File"),
                                                ".",
                                                tr("Text Files(*.txt)"));
    if(!path.isEmpty()) {
        QFile file(path);
        if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
            QMessageBox::warning(this, tr("Read File"),
                                 tr("Cannot open file:\n%1").arg(path));
            return;
        }
        QTextStream in(&file);
        textEdit->setText(in.readAll());
        file.close();
    } else {
        QMessageBox::warning(this, tr("Path"),
                             tr("You did not select any file."));
    }
}

void MainWindow::saveFile()
{
    QString path = QFileDialog::getSaveFileName(this,
                                                tr("Open File"),
                                                ".",
                                                tr("Text Files(*.txt)"));
    if(!path.isEmpty()) {
        QFile file(path);
        if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
            QMessageBox::warning(this, tr("Write File"),
                                       tr("Cannot open file:\n%1").arg(path));
            return;
        }
        QTextStream out(&file);
        out << textEdit->toPlainText();
        file.close();
    } else {
        QMessageBox::warning(this, tr("Path"),
                             tr("You did not select any file."));
    }
}







#include "mainwindow.h"
#include <QApplication>
#include <QSpinBox>
#include <QSlider>
#include <QHBoxLayout>

// !!! Qt 5

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    MainWindow win;
    win.show();

    return app.exec();
}





#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTextEdit>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
     MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    void openFile();
    void saveFile();
    QAction *openAction;
    QAction *saveAction;
    QTextEdit *textEdit;
};

#endif // MAINWINDOW_H

大概看了一下午。。。这东西看起来虽然说完全没难度。。。但是还是很麻烦啊。。。

代码

qt 5.x 初探(1)

qt 5.x　初探(1)