QT5 学习资料，包括基本知识的介绍、常用 GUI 组件的介绍、常用技术的介绍等；内容上将结合 Qt 4 与 Qt 5 两个部分。(QT5 learning materials, including introduction of basic knowledge, introduction of commonly used GUI components, introduction of common technologies, etc., will combine two parts of Qt 4 and Qt 5.)