QT standarddialgs

#ifndef WIDGET_H#define WIDGET_H#include <QWidget>#include <QPushButton>#include <QLineEdit>#include <QGridLayout>namespace Ui { class Widget;}class Widget : public QWidget{ Q_OBJECTpublic: explicit Widget(QWidget *parent = 0); ~Widget();private: Ui::Widget *ui;public : private slots: void slotOpenFileDlg(); void slotOpenColorDlg(); void slotOpenFontDlg();};#endif // WIDGET_H#include <QtGui/QApplication>#include "widget.h"int main(int argc, char *argv[]){ QApplication a(argc, argv); Widget w; w.show(); return a.exec();}#include "widget.h"#include "ui_widget.h"#include <QFileDialog>#include <QColor>#include <QFont>#include <QFontDialog>#include <QColorDialog>Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget){ setWindowTitle(tr("Standard Dialogs")); ui->setupUi(this); connect(ui->filePushButton,SIGNAL(clicked()),this,SLOT(slotOpenFileDlg())); connect(ui->colorPushButton,SIGNAL(clicked()),this,SLOT(slotOpenColorDlg())); connect(ui->fontPushButton,SIGNAL(clicked()),this,SLOT(slotOpenFontDlg())); connect(ui->exitPushButton,SIGNAL(clicked()),this,SLOT(close()));}Widget::~Widget(){ delete ui;}void Widget::slotOpenColorDlg(){ QColor color=QColorDialog::getColor(Qt::blue); if (color.isValid()){ this->setPalette(QPalette(color));}}void Widget::slotOpenFileDlg(){ QString s=QFileDialog::getOpenFileName(this,"open file dialog","/","C++ file(*.cpp);;C files(*.c);;Head files(*.h)"); ui->fileLineEdit->setText(s.toUtf8());}void Widget::slotOpenFontDlg(){ bool ok; QFont font=QFontDialog::getFont(&ok); if (ok) { ui->fontLineEdit->setFont(font); } }