QDialog、QLineEdit、QGridLayout、QPushButton的用法

dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QLineEdit>
#include <QGridLayout>

class Dialog : public QDialog
{
    Q_OBJECT

public:
    Dialog(QWidget *parent = 0);
    ~Dialog();
private:
    QPushButton *fileBtn;
    QLineEdit *fileLineEdit;
    QGridLayout *mainLayout;
    //
    QPushButton *colorBtn;
    QFrame *colorFrame;
    //
    QPushButton *fontBtn;
    QLineEdit *fontLineEdit;

private slots:
    void showFile();
    void showColor();
    void showFont();
};

#endif // DIALOG_H

dialog.app

#include "dialog.h"
#include <QPushButton>
#include <QGridLayout>
#include <QFileDialog>
#include <QColorDialog>
#include <QFontDialog>

Dialog::Dialog(QWidget *parent)
    : QDialog(parent)
{
    fileBtn=new QPushButton; //各个控件对象的初始化
    fileBtn->setText(tr("文件标准对话框实例"));
    fileLineEdit=new QLineEdit;
    mainLayout=new QGridLayout(this);
    mainLayout->addWidget(fileBtn,0,0);
    mainLayout->addWidget(fileLineEdit,0,1);
    connect(fileBtn,
            SIGNAL(clicked()),
            this,
            SLOT(showFile()));
    //Color Button
    colorBtn = new QPushButton;
    colorBtn->setText("颜色标准对话框实例");
    colorFrame= new QFrame;
    colorFrame->setFrameShape(QFrame::Box);
    colorFrame->setAutoFillBackground(true);
    mainLayout->addWidget(colorBtn,1,0);
    mainLayout->addWidget(colorFrame,1,1);

    connect(colorBtn,
            SIGNAL(clicked()),
            this,
            SLOT(showColor()));

    //Font
    fontBtn = new QPushButton;
    fontBtn->setText("字体标准对话框实例");
    fontLineEdit = new QLineEdit();
    fontLineEdit->setText("Welcome!");
    mainLayout->addWidget(fontBtn,2,0);
    mainLayout->addWidget(fontLineEdit,2,1);
    connect(fontBtn,
            SIGNAL(clicked()),
            this,
            SLOT(showFont()));


}
void Dialog::showFile()
{
    QString s = QFileDialog::getOpenFileName(this,
                                             "Open File Dialog",
                                             "/",
                                             "C++ files (*.cpp);;C Files (*.c);;Head files (*.h)");
    fileLineEdit->setText(s);
}

void Dialog::showColor()
{
    QColor c = QColorDialog::getColor(Qt::blue);
    if(c.isValid())
    {
        colorFrame->setPalette(QPalette(c));
    }
}

void Dialog::showFont()
{
    bool ok ;
    QFont f =QFontDialog::getFont(&ok);
    if(ok)
    {
        fontLineEdit->setFont(f);
    }
}

Dialog::~Dialog()
{

}