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>。
1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies). 4 ** Contact: http://www.qt-project.org/legal 5 ** 6 ** This file is part of the examples of the Qt Toolkit. 7 ** 8 ** $QT_BEGIN_LICENSE:BSD$ 9 ** You may use this file under the terms of the BSD license as follows: 10 ** 11 ** "Redistribution and use in source and binary forms, with or without 12 ** modification, are permitted provided that the following conditions are 13 ** met: 14 ** * Redistributions of source code must retain the above copyright 15 ** notice, this list of conditions and the following disclaimer. 16 ** * Redistributions in binary form must reproduce the above copyright 17 ** notice, this list of conditions and the following disclaimer in 18 ** the documentation and/or other materials provided with the 19 ** distribution. 20 ** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names 21 ** of its contributors may be used to endorse or promote products derived 22 ** from this software without specific prior written permission. 23 ** 24 ** 25 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." 36 ** 37 ** $QT_END_LICENSE$ 38 ** 39 ****************************************************************************/ 40 41 #include <QtWidgets> 42 #include <QTranslator> 43 #include <QLocale> 44 #include <QLibraryInfo> 45 46 47 QWizardPage *createIntroPage() 48 { 49 QWizardPage *page = new QWizardPage; 50 page->setTitle("Introduction"); 51 52 QLabel *label = new QLabel("This wizard will help you register your copy " 53 "of Super Product Two."); 54 label->setWordWrap(true); 55 56 QVBoxLayout *layout = new QVBoxLayout; 57 layout->addWidget(label); 58 page->setLayout(layout); 59 60 return page; 61 } 62 63 QWizardPage *createRegistrationPage() 64 { 65 QWizardPage *page = new QWizardPage; 66 page->setTitle("Registration"); 67 page->setSubTitle("Please fill both fields."); 68 69 QLabel *nameLabel = new QLabel("Name:"); 70 QLineEdit *nameLineEdit = new QLineEdit; 71 72 QLabel *emailLabel = new QLabel("Email address:"); 73 QLineEdit *emailLineEdit = new QLineEdit; 74 75 QGridLayout *layout = new QGridLayout; 76 layout->addWidget(nameLabel, 0, 0); 77 layout->addWidget(nameLineEdit, 0, 1); 78 layout->addWidget(emailLabel, 1, 0); 79 layout->addWidget(emailLineEdit, 1, 1); 80 page->setLayout(layout); 81 82 return page; 83 } 84 85 QWizardPage *createConclusionPage() 86 { 87 QWizardPage *page = new QWizardPage; 88 page->setTitle("Conclusion"); 89 90 QLabel *label = new QLabel("You are now successfully registered. Have a " 91 "nice day!"); 92 label->setWordWrap(true); 93 94 QVBoxLayout *layout = new QVBoxLayout; 95 layout->addWidget(label); 96 page->setLayout(layout); 97 98 return page; 99 } 100 101 int main(int argc, char *argv[]) 102 { 103 QApplication app(argc, argv); 104 105 QString translatorFileName = QLatin1String("qt_"); 106 translatorFileName += QLocale::system().name(); 107 QTranslator *translator = new QTranslator(&app); 108 if (translator->load(translatorFileName, QLibraryInfo::location(QLibraryInfo::TranslationsPath))) 109 app.installTranslator(translator); 110 111 QWizard wizard; 112 wizard.addPage(createIntroPage()); 113 wizard.addPage(createRegistrationPage()); 114 wizard.addPage(createConclusionPage()); 115 116 wizard.setWindowTitle("Trivial Wizard"); 117 #ifdef Q_OS_SYMBIAN 118 wizard.showMaximized(); 119 #else 120 wizard.show(); 121 #endif 122 123 return app.exec(); 124 }
然后程序就顺利运行了。