qmake Common Projects

This chapter describes how to set up qmake project files for three common project types that are based on Qt. Although all kinds of projects use many of the same variables, each of them use project-specific variables to customize output files.

Platform-specific variables are not described here; we refer the reader to the 部署 Qt 应用程序 document for information on issues such as building universal binaries for Mac OS X and handling Visual Studio manifest files .

构建应用程序

The app Template

The app template tells qmake to generate a Makefile that will build an application. With this template, the type of application can be specified by adding one of the following options to the CONFIG variable definition:

选项	描述
windows	应用程序是 Windows GUI 应用程序。
console	`app` 仅模板：应用程序是 Windows 控制台应用程序。

When using this template the following qmake system variables are recognized. You should use these in your .pro file to specify information about your application.

HEADERS - A list of all the header files for the application.
SOURCES - A list of all the source files for the application.
FORMS - A list of all the UI files (created using Qt Designer ) for the application.
LEXSOURCES - A list of all the lex source files for the application.
YACCSOURCES - A list of all the yacc source files for the application.
TARGET - Name of the executable for the application. This defaults to the name of the project file. (The extension, if any, is added automatically).
DESTDIR - The directory in which the target executable is placed.
DEFINES - A list of any additional pre-processor defines needed for the application.
INCLUDEPATH - A list of any additional include paths needed for the application.
DEPENDPATH - The dependency search path for the application.
VPATH - The search path to find supplied files.
DEF_FILE - Windows only: A .def file to be linked against for the application.
RC_FILE - Windows only: A resource file for the application.
RES_FILE - Windows only: A resource file to be linked against for the application.

You only need to use the system variables that you have values for, for instance, if you do not have any extra INCLUDEPATHs then you do not need to specify any, qmake will add in the default ones needed. For instance, an example project file might look like this:

TEMPLATE = app
DESTDIR  = c:/helloapp
HEADERS += hello.h
SOURCES += hello.cpp
SOURCES += main.cpp
DEFINES += QT_DLL
CONFIG  += qt warn_on release

For items that are single valued, e.g. the template or the destination directory, we use "="; but for multi-valued items we use "+=" to add to the existing items of that type. Using "=" replaces the item's value with the new value, for example if we wrote DEFINES=QT_DLL , all other definitions would be deleted.

构建库

The lib Template

The lib template tells qmake to generate a Makefile that will build a library. When using this template, in addition to the system variables mentioned above for the app template the VERSION variable is supported. You should use these in your .pro file to specify information about the library.

当使用 lib template, the following options can be added to the CONFIG variable to determine the type of library that is built:

选项	描述
dll	库是 DLL 共享库。
staticlib	库是静态库。
plugin	The library is a plugin; this also enables the dll option.

The following option can also be defined to provide additional information about the library.

VERSION - The version number of the target library, for example, 2.3.1.

The target file name for the library is platform-dependent. For example, on X11 and Mac OS X, the library name will be prefixed by lib ; on Windows, no prefix is added to the file name.

构建插件

Plugins are built using the lib template, as described in the previous section. This tells qmake to generate a Makefile for the project that will build a plugin in a suitable form for each platform, usually in the form of a library. As with ordinary libraries, the VERSION variable is used to specify information about the plugin.

VERSION - The version number of the target library, for example, 2.3.1.

构建 Qt Designer 插件

Qt Designer plugins are built using a specific set of configuration settings that depend on the way Qt was configured for your system. For convenience, these settings can be enabled by adding designer to the project's CONFIG variable. For example:

CONFIG      += designer plugin

见 Qt Designer 范例 for more examples of plugin-based projects.

在调试和发行模式下构建和安装

Sometimes, it is necessary to build a project in both debug and release modes. Although the CONFIG variable can hold both debug and release options, the debug option overrides the release 选项。

在 2 种模式下构建

To enable a project to be built in both modes, you must add the debug_and_release option to your project's CONFIG 定义：

CONFIG += debug_and_release
CONFIG(debug, debug|release) {
    TARGET = debug_binary
} else {
    TARGET = release_binary
}

The scope in the above snippet modifies the build target in each mode to ensure that the resulting targets have different names. Providing different names for targets ensures that one will not overwrite the other.

当 qmake processes the project file, it will generate a Makefile rule to allow the project to be built in both modes. This can be invoked in the following way:

make all

The build_all option can be added to the CONFIG variable in the project file to ensure that the project is built in both modes by default:

CONFIG += build_all

This allows the Makefile to be processed using the default rule:

make

在 2 种模式下安装

The build_all option also ensures that both versions of the target will be installed when the installation rule is invoked:

make install

It is possible to customize the names of the build targets depending on the target platform. For example, a library or plugin may be named using a different convention on Windows to the one used on Unix platforms:

CONFIG(debug, debug|release) {
    mac: TARGET = $$join(TARGET,,,_debug)
    win32: TARGET = $$join(TARGET,,d)
}

The default behavior in the above snippet is to modify the name used for the build target when building in debug mode. An else clause could be added to the scope to do the same for release mode; left as it is, the target name remains unmodified.