Introduction to the basic application and skills of QT

1 .pro file

In the use of Qt Wizard generated applications .pro The file format is as follows ：

QT       += core gui  // Included modules 
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets // Greater than Qt4 edition   To include widget modular 
TARGET = QtFirst  // Application name    Generated .exe Program name 
TEMPLATE = app    // Template type      Application template 
SOURCES += main.cpp\   // Source file 
        mywidget.cpp
HEADERS  += mywidget.h   // The header file 

.pro It's engineering documents (project), It is qmake Automatically generated for production makefile Configuration file for ..pro The document is written as follows ：
• notes
from “#” Start , By the end of the line .
• The template variable tells qmake What kind of... Is generated for this application makefile. Here are the options available ：TEMPLATE = app

    ◦ app - Build an application of makefile. This is the default , So if the template is not specified , This will be used .
    ◦ lib -  Build a library of makefile.
    ◦ vcapp -  Build an application of VisualStudio Project documents .
    ◦ vclib -  Build a library of VisualStudio Project documents .
    ◦ subdirs - This is a special template , It can create a directory that can enter a specific directory and generate... For a project file makefile And call... For it make Of makefile.

•# Specify the name of the generated application ：
TARGET = QtDemo
• # The header file included in the project
HEADERS += include/painter.h
• # The project includes .ui Design documents
FORMS += forms/painter.ui
• # Source files included in the project
SOURCES += sources/main.cpp sources
• # Resource files included in the project
RESOURCES += qrc/painter.qrc
• greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
The meaning of this sentence is , If QT_MAJOR_VERSION Greater than 4（ That is, the current Qt5 And higher ） Need to increase the widgets modular . If the project only needs support Qt5, You can also add “QT += widgets” A word of . But to keep the code compatible , It's better to follow QtCreator The generated statements are written .
• # Configuration information
CONFIG To tell qmake Configuration information about the application .
CONFIG += c++11 // Use c++11 Characteristics of
Use it here “+=”, It's because we add our configuration options to any one that already exists . This is better than using “=” So it's safer to replace all the options that have been specified .

2 One of the simplest Qt Applications

3 Naming conventions and shortcut keys