VS2012下QT creator登录对话框设计

#include "user.h"
#include <QtWidgets/QApplication>
#include "logindlg.h"

int main(int argc, char *argv[])
{
  QApplication a(argc, argv);
  User w;
  loginDlg login;
  if(login.exec() == QDialog::Accepted)
  {
  w.show();
  return a.exec();
  }
  else return 0;
}

#ifndef LOGINDLG_H
#define LOGINDLG_H

#include <QDialog>
#include "ui_logindlg.h"

class loginDlg : public QDialog
{
  Q_OBJECT

public:
  loginDlg(QWidget *parent = 0);
  ~loginDlg();

private:
  Ui::loginDlg *ui; //这里定义ui为指向类的指针
private slots:
  void on_loginBtn_clicked(); //槽函数声明
};

#endif // LOGINDLG_H

void loginDlg::on_loginBtn_clicked()
{
  if(ui->usrLineEdit->text() == tr("caddress")&&ui->pwdLineEdit->text()==tr("123456"))
    accept();
  else{
    QMessageBox::warning(this,tr("Warning"),tr("user name or password error!")，QMessageBox::Yes):
  }
}

#include "logindlg.h"
#include <qmessagebox> //添加该头文件才能使用QMessageBox

loginDlg::loginDlg(QWidget *parent)
 : QDialog(parent)
{
 (*ui).setupUi(this); //这里ui需要为类类型，所以得解指针
}

loginDlg::~loginDlg()
{

}

void loginDlg::on_loginBtn_clicked()
{
 if(ui->usrLineEdit->text() == tr("caddress")&&ui->pwdLineEdit->text()==tr("123456")) //这里需要指针，直接使用ui
  accept();
 else{
  QMessageBox::warning(this,tr("Warning"),tr("user name or password error!"),QMessageBox::Yes);
 }
}