【QT】C++ GUI Qt4 学习笔记1

Find对话框实现 平台 Qt5.3.2 MinGW4.8.2

注意创建时用QDialog

finddialog.h

#ifndef FINDDIALOG_H
#define FINDDIALOG_H

#include <QDialog>
#include <QLabel>
#include <QCheckBox>
#include <QLineEdit>
#include <QPushButton>
#include <QLayout>

class FindDialog : public QDialog
{
    Q_OBJECT
public:
    FindDialog(QWidget * parent = 0);
signals:
    void findNext(const QString &str, Qt::CaseSensitivity cs);
    void findPrevious(const QString &str, Qt::CaseSensitivity cs);
private slots:
    void findClicked();
    void enableFindButton(const QString &text);
private:
    QLabel * label;
    QLineEdit * lineEdit;
    QCheckBox * caseCheckBox;
    QCheckBox * backwardCheckBox;
    QPushButton * findButton;
    QPushButton * closeButton;
};

#endif // FINDDIALOG_H

finddialog.cpp

#include <QtGui>
#include "finddialog.h"

FindDialog::FindDialog(QWidget *parent):QDialog(parent)
{
    label = new QLabel(tr("Find &what:"));
    lineEdit = new QLineEdit;
    label->setBuddy(lineEdit);

    caseCheckBox = new QCheckBox(tr("Match &case"));
    backwardCheckBox = new QCheckBox(tr("Search &backward"));

    findButton = new QPushButton(tr("&Find"));
    findButton->setDefault(true);
    findButton->setEnabled(false);

    closeButton = new QPushButton(tr("Close"));

    connect(lineEdit, SIGNAL(textChanged(const QString &)),
            this, SLOT(enableFindButton(const QString &)));
    connect(findButton, SIGNAL(clicked()), this, SLOT(findClicked()));
    connect(closeButton, SIGNAL(clicked()), this, SLOT(close()));

    QHBoxLayout * topLeftLayout = new QHBoxLayout;
    topLeftLayout->addWidget(label);
    topLeftLayout->addWidget(lineEdit);

    QVBoxLayout * leftLayout = new QVBoxLayout;
    leftLayout->addLayout(topLeftLayout);
    leftLayout->addWidget(caseCheckBox);
    leftLayout->addWidget(backwardCheckBox);

    QVBoxLayout * rightLayout = new QVBoxLayout;
    rightLayout->addWidget(findButton);
    rightLayout->addWidget(closeButton);
    rightLayout->addStretch();

    QHBoxLayout * mainLayout = new QHBoxLayout;
    mainLayout->addLayout(leftLayout);
    mainLayout->addLayout(rightLayout);
    setLayout(mainLayout);
    setWindowTitle(tr("Find"));
    setFixedHeight(sizeHint().height());
}

void FindDialog::findClicked()
{
    QString text = lineEdit->text();
    Qt::CaseSensitivity cs = caseCheckBox->isChecked()?Qt::CaseSensitive
                                                     :Qt::CaseInsensitive;
    if(backwardCheckBox->isChecked())
    {
        emit findPrevious(text, cs);
    }
    else
    {
        emit findNext(text, cs);
    }
}

void FindDialog::enableFindButton(const QString &text)
{
    findButton->setEnabled(!text.isEmpty());
}

mian.cpp

#include "finddialog.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    FindDialog *dialog = new FindDialog;
    dialog->show();

    return a.exec();
}