[img]http://dl.iteye.com/upload/attachment/507494/6767a589-f46b-33c1-acf2-4d3c755ad2d5.png

dialog.h 

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <boost/scoped_ptr.hpp>
using namespace boost;

namespace Ui {

}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
private slots:
    void on_lineEdit_textChanged ( const QString & text );
private:
    class DialogUi;
    scoped_ptr<DialogUi> mui;
    class DialogData;
    scoped_ptr<DialogData> mData;
};

#endif // DIALOG_H



dialog.cpp


#include "dialog.h"
#include<QPushButton>
#include "ui_dialog.h"

class Dialog::DialogUi:public Ui::Dialog{};

class Dialog::DialogData{

};

Dialog::Dialog(QWidget *parent) :
    QDialog(parent)
{
    mui.reset(new DialogUi);
    //setupUi会自动将那些符合on_ObjectName_signalName()命名习惯的槽与相应的信号相连接
    mui->setupUi(this);
    mui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(false);
    QRegExp regExp("[a-Z][1-9][0-9]{0,2}");
    mui->lineEdit->setValidator(new QRegExpValidator(regExp,this));
    connect(mui->buttonBox,SIGNAL(accepted()),this,SLOT(accept()));
    connect(mui->buttonBox,SIGNAL(rejected()),this,SLOT(reject()));
}

void Dialog::on_lineEdit_textChanged(const QString &text)
{
    mui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(
                mui->lineEdit->hasAcceptableInput());
}

Dialog::~Dialog()
{
}


main.cpp


#include <QtGui/QApplication>
#include "dialog.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Dialog w;
    w.show();

    return a.exec();
}