QT小例子 文件查找

先看看效果图吧，可以查找文件，以及通过文件内容进行查找

#ifndef WINDOW_H
#define WINDOW_H

#include <QDialog>
#include <QDir>

QT_BEGIN_NAMESPACE
class QComboBox;
class QLabel;
class QPushButton;
class QTableWidget;
class QTableWidgetItem;
QT_END_NAMESPACE

//! [0]
class Window : public QDialog
{
    Q_OBJECT

public:
    Window(QWidget *parent = 0);

private slots:
    void browse();
    void find();
    void openFileOfItem(int row, int column);

private:
    QStringList findFiles(const QStringList &files, const QString &text);
    void showFiles(const QStringList &files);
    QPushButton *createButton(const QString &text, const char *member);
    QComboBox *createComboBox(const QString &text = QString());
    void createFilesTable();

    QComboBox *fileComboBox;
    QComboBox *textComboBox;
    QComboBox *directoryComboBox;
    QLabel *fileLabel;
    QLabel *textLabel;
    QLabel *directoryLabel;
    QLabel *filesFoundLabel;
    QPushButton *browseButton;
    QPushButton *findButton;
    QTableWidget *filesTable;

    QDir currentDir;
};
//! [0]

#endif

#include <QtGui>

#include "window.h"

//! [0]
Window::Window(QWidget *parent)
    : QDialog(parent)
{
    browseButton = createButton(tr("&Browse..."), SLOT(browse()));
    findButton = createButton(tr("&Find"), SLOT(find()));

    fileComboBox = createComboBox(tr("*"));
    textComboBox = createComboBox();
    directoryComboBox = createComboBox(QDir::currentPath());

    fileLabel = new QLabel(tr("Named:"));
    textLabel = new QLabel(tr("Containing text:"));
    directoryLabel = new QLabel(tr("In directory:"));
    filesFoundLabel = new QLabel;

    createFilesTable();
//! [0]

//! [1]
    QHBoxLayout *buttonsLayout = new QHBoxLayout;
    buttonsLayout->addStretch();
    buttonsLayout->addWidget(findButton);

    QGridLayout *mainLayout = new QGridLayout;
    mainLayout->addWidget(fileLabel, 0, 0);
    mainLayout->addWidget(fileComboBox, 0, 1, 1, 2);
    mainLayout->addWidget(textLabel, 1, 0);
    mainLayout->addWidget(textComboBox, 1, 1, 1, 2);
    mainLayout->addWidget(directoryLabel, 2, 0);
    mainLayout->addWidget(directoryComboBox, 2, 1);
    mainLayout->addWidget(browseButton, 2, 2);
    mainLayout->addWidget(filesTable, 3, 0, 1, 3);
    mainLayout->addWidget(filesFoundLabel, 4, 0, 1, 3);
    mainLayout->addLayout(buttonsLayout, 5, 0, 1, 3);
    setLayout(mainLayout);

    setWindowTitle(tr("Find Files"));
    resize(700, 300);
}
//! [1]

//! [2]
void Window::browse()
{
    QString directory = QFileDialog::getExistingDirectory(this,
                               tr("Find Files"), QDir::currentPath());

    if (!directory.isEmpty()) {
        if (directoryComboBox->findText(directory) == -1)
            directoryComboBox->addItem(directory);
        directoryComboBox->setCurrentIndex(directoryComboBox->findText(directory));
    }
}
//! [2]

static void updateComboBox(QComboBox *comboBox)
{
    if (comboBox->findText(comboBox->currentText()) == -1)
        comboBox->addItem(comboBox->currentText());
}

//! [3]
void Window::find()
{
    filesTable->setRowCount(0);

    QString fileName = fileComboBox->currentText();
    QString text = textComboBox->currentText();
    QString path = directoryComboBox->currentText();
//! [3]

    updateComboBox(fileComboBox);
    updateComboBox(textComboBox);
    updateComboBox(directoryComboBox);

//! [4]
    currentDir = QDir(path);
    QStringList files;
    if (fileName.isEmpty())
        fileName = "*";
    files = currentDir.entryList(QStringList(fileName),
                                 QDir::Files | QDir::NoSymLinks);

    if (!text.isEmpty())
        files = findFiles(files, text);
    showFiles(files);
}
//! [4]

//! [5]
QStringList Window::findFiles(const QStringList &files, const QString &text)
{
    QProgressDialog progressDialog(this);
    progressDialog.setCancelButtonText(tr("&Cancel"));
    progressDialog.setRange(0, files.size());
    progressDialog.setWindowTitle(tr("Find Files"));

//! [5] //! [6]
    QStringList foundFiles;

    for (int i = 0; i < files.size(); ++i) {
        progressDialog.setValue(i);
        progressDialog.setLabelText(tr("Searching file number %1 of %2...")
                                    .arg(i).arg(files.size()));
        qApp->processEvents();
//! [6]

        if (progressDialog.wasCanceled())
            break;

//! [7]
        QFile file(currentDir.absoluteFilePath(files[i]));

        if (file.open(QIODevice::ReadOnly)) {
            QString line;
            QTextStream in(&file);
            while (!in.atEnd()) {
                if (progressDialog.wasCanceled())
                    break;
                line = in.readLine();
                if (line.contains(text)) {
                    foundFiles << files[i];
                    break;
                }
            }
        }
    }
    return foundFiles;
}
//! [7]

//! [8]
void Window::showFiles(const QStringList &files)
{
    for (int i = 0; i < files.size(); ++i) {
        QFile file(currentDir.absoluteFilePath(files[i]));
        qint64 size = QFileInfo(file).size();

        QTableWidgetItem *fileNameItem = new QTableWidgetItem(files[i]);
        fileNameItem->setFlags(fileNameItem->flags() ^ Qt::ItemIsEditable);
        QTableWidgetItem *sizeItem = new QTableWidgetItem(tr("%1 KB")
                                             .arg(int((size + 1023) / 1024)));
        sizeItem->setTextAlignment(Qt::AlignRight | Qt::AlignVCenter);
        sizeItem->setFlags(sizeItem->flags() ^ Qt::ItemIsEditable);

        int row = filesTable->rowCount();
        filesTable->insertRow(row);
        filesTable->setItem(row, 0, fileNameItem);
        filesTable->setItem(row, 1, sizeItem);
    }
    filesFoundLabel->setText(tr("%1 file(s) found").arg(files.size()) +
                             (" (Double click on a file to open it)"));
}
//! [8]

//! [9]
QPushButton *Window::createButton(const QString &text, const char *member)
{
    QPushButton *button = new QPushButton(text);
    connect(button, SIGNAL(clicked()), this, member);
    return button;
}
//! [9]

//! [10]
QComboBox *Window::createComboBox(const QString &text)
{
    QComboBox *comboBox = new QComboBox;
    comboBox->setEditable(true);
    comboBox->addItem(text);
    comboBox->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
    return comboBox;
}
//! [10]

//! [11]
void Window::createFilesTable()
{
    filesTable = new QTableWidget(0, 2);
    filesTable->setSelectionBehavior(QAbstractItemView::SelectRows);

    QStringList labels;
    labels << tr("File Name") << tr("Size");
    filesTable->setHorizontalHeaderLabels(labels);
    filesTable->horizontalHeader()->setResizeMode(0, QHeaderView::Stretch);
    filesTable->verticalHeader()->hide();
    filesTable->setShowGrid(false);

    connect(filesTable, SIGNAL(cellActivated(int,int)),
            this, SLOT(openFileOfItem(int,int)));
}
//! [11]

//! [12]

void Window::openFileOfItem(int row, int /* column */)
{
    QTableWidgetItem *item = filesTable->item(row, 0);

    QDesktopServices::openUrl(QUrl::fromLocalFile(currentDir.absoluteFilePath(item->text())));
}

//! [12]

#include <QApplication>

#include "window.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}