Qt5中的QtGui

我在学习Qt查看Qt Creater提供的例子时，遇到了一个小问题。就是明明在代码中包含了QtGui，然而编译的时候还是提示找不到QLabel的定义，以及其他一些类的定义，但是这是官方提供的文档的啊，不应该没通过编译就提供吧，所以就想肯定是自己哪里出了问题，在网上搜了一下果然，归根到底还是版本问题吧，提供的文档估计是版本qt4的，而我自己使用的是qt5，它两个之间的一个区别就是Qt5把关于控件的头文件都移到 <QtWidgets>中了，所以如果在 Qt5 中使用控件应该包含 <QtWidgets>而非<QtGui>。

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  ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
  ** Contact: http://www.qt-project.org/legal
  **
  ** This file is part of the examples of the Qt Toolkit.
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 #include <QtWidgets>
 #include <QTranslator>
 #include <QLocale>
 #include <QLibraryInfo>

  QWizardPage *createIntroPage()
  {
      QWizardPage *page = new QWizardPage;
      page->setTitle("Introduction");

      QLabel *label = new QLabel("This wizard will help you register your copy "
                                 "of Super Product Two.");
      label->setWordWrap(true);

      QVBoxLayout *layout = new QVBoxLayout;
      layout->addWidget(label);
      page->setLayout(layout);

      return page;
  }

  QWizardPage *createRegistrationPage()
  {
      QWizardPage *page = new QWizardPage;
      page->setTitle("Registration");
      page->setSubTitle("Please fill both fields.");

      QLabel *nameLabel = new QLabel("Name:");
      QLineEdit *nameLineEdit = new QLineEdit;

      QLabel *emailLabel = new QLabel("Email address:");
      QLineEdit *emailLineEdit = new QLineEdit;

      QGridLayout *layout = new QGridLayout;
      layout->addWidget(nameLabel, , );
      layout->addWidget(nameLineEdit, , );
      layout->addWidget(emailLabel, , );
      layout->addWidget(emailLineEdit, , );
      page->setLayout(layout);

      return page;
  }

  QWizardPage *createConclusionPage()
  {
      QWizardPage *page = new QWizardPage;
      page->setTitle("Conclusion");

      QLabel *label = new QLabel("You are now successfully registered. Have a "
                                 "nice day!");
      label->setWordWrap(true);

      QVBoxLayout *layout = new QVBoxLayout;
      layout->addWidget(label);
      page->setLayout(layout);

      return page;
  }

  int main(int argc, char *argv[])
  {
      QApplication app(argc, argv);

      QString translatorFileName = QLatin1String("qt_");
      translatorFileName += QLocale::system().name();
      QTranslator *translator = new QTranslator(&app);
      if (translator->load(translatorFileName, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
          app.installTranslator(translator);

      QWizard wizard;
      wizard.addPage(createIntroPage());
      wizard.addPage(createRegistrationPage());
      wizard.addPage(createConclusionPage());

      wizard.setWindowTitle("Trivial Wizard");
  #ifdef Q_OS_SYMBIAN
      wizard.showMaximized();
  #else
      wizard.show();
  #endif

      return app.exec();
  }

然后程序就顺利运行了。